MacGyver needs a distraction to escape from a cabin in the woods (surrounded by bad guys). He puts some chemicals into an iron stove and rolls it out the door.
The stove explodes when someone shoots inside of it—it’s not because of the spark from a bullet (because they don’t really do that). No, the bullet has to puncture the can of stuff in there to mix the chemicals. That’s what causes the explosion.
Also, a quick note—that stump remover is some bad stuff.
Cheese puffs to get past phone lock screen
How do you find someone’s pin code? MacGyver crushes up some cheese puffs and sprinkles them on a phone screen. The oil from someone’s fingers leave some residue that makes the cheese puff crumbs stick to the phone.
Now you know which numbers are used in the pin code—you still have to figure out the order (and this case it was three numbers so there was one used twice). But MacGyver figures that it’s an important number.