Go cheap on some insense sticks perhaps?
im gone.

Quoted from Greg Hanson, owner of some actual GB Props. With corisponding pictures on the GBPA.

“here's the first pic of my trap from the second film. all the remaining pics will be of this trap. this is a pic of the left side, snapped onto dan aykroyd's belt. the cloth/rubber strips you see on each side and in front of the doors are for the smoking effect. some sort of chemical was poured onto these strips, and it would in turn ”smoke“ for a few seconds (long enough to get the shots they needed). the prop guy didn't remember what the chemical was though. the doors do not open on this trap, and this one is of fiberglass construction. the one from the first film is all metal (and kinda heavy). this trap is also considerably smaller that the first film version.”


In a remembered conversation with Harold Ramis, he explained that the traps were remotely controlled with a simple smoke bombs used for the smoke effect. (But I cannot be certain about this).

I like back's idea. Inscents won't turn off the crowds.

i do remember Harold Ramis sayhing something about smoke bombs, but i dont remember him talking about the traps, but if u look at the scene after they atch slimer and tlaking to the guy abotu payment u cans see them strips on the trap.