The worst I did.... junior high science teacher passed out a big spool of magnesium tape. Told us to cut off one inch of it and light it with the Bunsen burner to see how brightly magnesium burned. I lit the entire spool on fire which ended up looking like the sun had landed in the classroom and was burning its way to the center of the earth. The science teacher was secretly thrilled with my antics I am grateful to him to this day for that.
My mom worked at a grocery store and for a few years when I was in 5th and 6th grade it was the last stop on a cooler truck's route. The driver would always leave the leftover dry ice and my mom would bring it home for me, sometimes a few pounds of it.
Things I was lucky to still have by the end of that period included fingers, a tongue, and functioning plumbing what with all the dry ice I flushed down the toilet.
The best thing to do was to get a good, solid 8oz food container like this:
http://cdnimg2.webstaurantstore.com/images/products/main/66759 /372182/8-oz-newspring-l5008y-delitainer-translucent-round-deli-co ntainer-48-pack.jpg
not the shitty kind they give you at the grocery store these days, one with a really tight lid. Fill it half full of hot water, put in a piece of dry ice about the size of a golf ball, close it up tight as fast as possible and then throw in up in the air like a frisbee as hard as you can so it blows the lid off up there and makes a big cloud of fog.