how about doing a chlorine bomb in slow motion.

I've actually made these, and I gotta say, it's much more of an explosion than the dry ice bomb.

It's 1 part powder style pool chlorine, 1 part household sugar, and 1 part water. You can make them in any size. 20oz bottle, and 2 liter bottle are the ones most people try. I was just watching the dry ice bomb episode, and I think the chlorine bomb is way better of a homemade bomb.