The way it worked was you tightly fit a shower curtain over the lid end of the bin, and cut a hole on the bottom of the bin. Then you get a smoke machine and fill up the inside of the bin with smoke. Then what you did was whack the shower curtain on the bin and a small ring of smoke would pop out and go flying off!
Room 15 got the honor of making one of the bins so we got to use it first! Some people put cups on their heads and the people holding the bins knocked them off. It looked so awesome and everyone had a great time using them. (except the people who didn't use them!)