Locker and crate smokes/foams

[KikiMofo]

I think it would be cool if when you mix a foam or smoke inside of a locker or crate it should stay inside the crate or locker until they are opened and then when they are opened they burst out. I can just imagine some fun fucking traps like leaving a note near a locker saying DON'T OPEN and of course someone opens it and they are consumed by a fire filled hellfoam. Let me know what you guys think.