The second test involved a second Impala with six rockets attached, launched off a giant ramp as in the Supersized Myths special. This time, the car hit the ramp perfectly straight and was launched into the air, but it immediately began tumbling and landed about 600 feet (180 m) away. The team came to the conclusion that the myth scenario is impossible simply because cars are not shaped like rockets and are therefore not aerodynamic in a way that supports flight.

Next, they enlisted 16 volunteers to have their hands sprayed with a harmless strain of Escherichia coli bacteria, then swabbed for a sample, then washed using water but no soap, then swabbed again, then dried using paper towels, then swabbed a third time. Then they repeated the process with the same volunteers, bacteria and washing technique, but using hand dryers instead. On average, the paper towels removed 71% of the bacteria on the volunteers' hands, while the hand dryers only removed 23%, confirming the first part of the myth.

Samples taken from swabbing the testing areas yielded 3 for the paper towels and 41 for the hand dryers, confirming the second part.

Then they retested with a new house with a wooden frame, and the mannequin standing inside was soon dispatched, but the doorway and table mannequins remained intact. After a final shake with enough force to simulate a magnitude 9.5 earthquake, the doorway mannequin fell over, leaving the under-the-table mannequin the last one to survive. Despite the doorway testing as the best spot in the masonry house, the Build Team declared the myth busted due to the high rarity of such houses in current times.

For the full-scale experiment, Adam and Jamie modified the Beast (previously seen in the final JATO Rocket Car revisit) with a large steel plate welded in front. When they used the Beast to T-bone the actual car from the movie at 50 miles per hour (80 km/h), the MythBusters (to their shock) achieved the opposite result: A simulated cadaver placed between two 350 lb (159 kg) simulated policemen (crafted by Adam and Jamie out of foam and rubber, then filled with water) in the backseat sustained more lethal injuries (including a full decapitation) and maxed out g-force sensors at over 800 g, as compared with a control test with the simulated cadaver alone in the backseat (where the damage and g-force numbers at 500–600 g, while still very much lethal, were noticeably better). Jamie speculated the reason for this may be the human body largely being made up of water and water's lack of compressibility, thus making the human body ineffective as a cushion.

They then proceeded to perform tests on two different vehicles (Kari and Grant in a new vehicle, Tory in an older vehicle with 75,000 miles (121,000 km) on the engine) comparing standard driving with a combination of all hypermiling techniques, with each car getting 3-US-gallon (11 L) of gas for both the control and hypermiling test. Kari and Grant's car traveled 64 miles (103 km) for the control and 90 miles (140 km) for the hypermiling test (a 40% gain), compared with Tory's figures of 78 miles (126 km) and 136 miles (219 km) respectively (a 70% gain). Despite declaring the myth busted, the Build Team noted the effectiveness of hypermiling techniques in improving the fuel efficiency of a car.

So to brave the rapids, they built two separate crafts out of bubble wrap pontoons held together by duct tape: Jamie made a large raft that resembled an inflatable pool sofa, and Adam constructed a long kayak. They each took their boats out onto the river and paddled downstream, where they repeatedly faced rapids of increasing difficulty, until they eventually reached a Class 5 rapid. Adam rode first, but his boat soon flipped and he fell out, forcing him to ride the rest of the rapids outside of the boat. He managed to survive, and found a large rock afterwards on which to rest and reenter the boat. Jamie handled the rapids by using the rocks to stand on as he carried his boat through narrow gaps, then rode the rest of the way without any problems.

They discovered a waterfall soon after, and decided to bypass it on land instead of attempting to ride down. They used some more rope to climb down a 25 feet (7.6 m) cliff past the waterfall, after which they paddled their boats out of the canyon and headed for civilization.

Jamie first experimented with various nozzle shapes until he found one that created a large, rectangular spread of paint. He also conducted preliminary tests at the bomb range, using a scuba tank filled with explosives with the nozzle attached, but it failed to paint the wall in a better spread than a scuba tank without the nozzle. Jamie surmised that the energy from the explosive wasn't properly spraying the paint out through the nozzle in the intended fashion because the scuba tank was cylindrical, so he built a large, heavy-duty spherical tank (dubbed a Death Star by J.D. Nelson) out of specially cut steel circles with nozzles in four directions. He then placed his tank within a small room with four walls, with the nozzles facing the walls, and placed dynamite and paint inside the tank. When the dynamite went off, the paint sprayed to cover hardly any of the area of the walls.

To split the boat once and for all, they traveled to the New Mexico Institute of Mining and Technology to use their rocket sled. Instead of propelling the boat towards a channel marker (fearing that the boat would disintegrate), they placed a metal pole on the sled and propelled it using two rocket motors. It traveled toward the boat at 200 miles per hour (320 km/h) and finally split the boat in two.

At UC-Berkeley, Adam and Jamie observed as 100-mL portions of the acid were poured onto samples of seven materials that would have been present in the bathroom: steel, wood, linoleum, drywall, ceramic-coated cast iron, ceramic alone, and pig flesh (to represent the human body). After 8 hours of soaking, the materials had deteriorated to various degrees, but none had been completely destroyed. Adam noted that although fluorine is the most reactive of the halogens, it forms the weakest acid of the group when it combines with hydrogen.

Jamie brought in a load of concentrated sulfuric acid, along with a second chemical that he referred to as "special sauce" to increase its corrosive ability. He and Adam built a bathroom set at a sanitary landfill, with a catch tank to contain any spills, and filled its cast-iron tub with 35 pounds (16 kg) of pig carcass parts and 6 US gallons (23 L) of the acid/"sauce" mixture. This liquid volume was three times the amount used in the actual scene. The tub contents eventually began to bubble, smoke, and give off large amounts of heat; however, some solid material remained after 20 minutes and neither the tub nor the floor leaked.

Acting on suggestions from Vince and Aaron, Adam and Jamie decided to use a larger quantity of acid/"sauce" (36 US gallons (140 L)) and a tub made from a more susceptible material. Fiberglass degraded quickly when exposed to the acid, so the two set up a full-scale test using it for their tub. Once the mixture was added, the reaction was so vigorous that the entire set was briefly hidden under thick clouds of smoke. After 5 minutes, Adam and Jamie found only a black organic sludge in the tub; although large amounts of liquid had boiled over the side, neither the tub nor the floor had been eaten through. Since they were unable to replicate the scene, they declared the myth busted.

Although the "sauce" was never explicitly identified, Jamie mentioned that the "sauce" had a lot of hydrogen and oxygen, and Adam said the concentration was 30%.^{[citation needed]} Based on this description, the chemical being referred to was likely hydrogen peroxide, thus creating a solution commonly known as piranha solution (confirmed at Adam Savage's San Diego Comic Con 2015 panel^[8]). Jamie noted that what he and Adam saw in the aftermath in the tub matched in contents with what fell through the ceiling after the reaction in the episode.

Grant built a robot to throw the charge down with typical human force, while Kari and Tory built a room identical to the one used in the show scene. They placed mannequins at appropriate positions and set rupture discs next to each, calibrated to burst at 13 pounds per square inch (90 kPa) (injury) and 75 pounds per square inch (520 kPa) (death). A charge of 50 grams failed to explode when thrown down, but Vince imagined that Walter may have mixed a quantity of even more sensitive silver fulminate into the batch. The team fitted their 50-gram charge with a blasting cap to ensure it would explode, then set it off. The "injury" discs burst on this trial, but none of the windows blew out.

In an attempt to replicate the explosion in the scene, Jesse made a 250-gram batch and the team set it off as in the second trial. This time, the resulting explosion broke the windows, burst every rupture disc, and blew the walls and ceiling apart. Because 5 times more explosive was required than used in the show, the team declared the myth busted.

For the test itself, Adam and Jamie marked off a "human zone" 30 feet (9.1 m) in diameter inside a hangar. On start, the zombies would approach the human zone, with Adam and Jamie forbidden from engaging a zombie until it entered the human zone. Adam (using the foam axe) averaged 14 kills across two runs, while Jamie (using a modified shotgun) only averaged 7 kills across two runs. Despite declaring the myth confirmed, Adam and Jamie would acknowledge practical limitations and issues with the parameters of the test in the episode's aftershow.^[9]

The zombie threat was simulated by small brains attached to their clothes; allowing a zombie to grab one would be counted as failure. Kari successfully crossed a horde similar in density to the population of Manhattan, while Tory survived a horde the density of overpopulated areas of Mumbai. However, Grant, faced with the highest density known to mankind – 180,000 people per square mile – was unsuccessful in escaping the horde.

The team then tried various techniques to see if they could divert the horde's attention away from them so as to successfully traverse this largest population density. Kari used Tory as a sacrifice and Grant used a robotic decoy; both tactics were successful. Tory opted to disguise himself as a zombie and blend in with the horde, but was recognized midway through his run and could not escape. Despite this, the team declared the myth busted since the horde could be escaped from through both speed and technique.

On the first run, using rickety wood doors held in place by a single two-by-four, the doors gave way almost immediately when the zombie horde haphazardly pushed up against it. The second run, using doors of more robust wood with a single two-by-four, didn't fare much better, as it gave way with a single coordinated push by the horde. However, after Jamie and Michael reinforced the second set of doors with as much available wood as was on hand, the horde was unable to penetrate the doors on the third run, thus busting the myth.