The allure of Pop Rocks is undeniable. Sure, the whole "fireworks in your mouth" thing is a gimmick, but it's an awesome one. You know what else is an awesome gimmick? Everybody's favourite Red Hot Nickel Ball.
The results aren't especially explosive, but those rocks still pop. Except instead of saliva, they're popping in a molten lava flow of liquid sugar fuelled by red hot metal. I bet there's only one of those that you want in your mouth. [Cars and Water]