In this case: "What happens if crankcase is full of off the shelf additives?" Plus a huge variety of other useless, but fun to watch stuff.
Let me be clear - none of their "testing" should be considered seriously. But for entertainment - I find them fun. It's always fun to see engines blow up, on someone else's dime. Garage 54 happens to have plenty of those dimes & engines rolling around. To answer the "What If?" questions that some gearheads may get while scrolling through their phone on the toilet lol.