Some cans of shaving cream can be frozen and they will pop open along the seams allowing the frozen block of foam to be very carefully removed for placement wherever. For example, someone's desk. When they open the drawer, the cream will come boiling out the top. Not that I ever did this to my superiors while in the military or anything..... Likewise, I never cut a piece of bologna to fit in the mouthpiece of their phone in such a way as to not muffle their voice during a call.