When I was a kid I put some calcium carbide into a plastic gallon milk jug and added water and screwed the cap on. Poked a hole in the side so the gas could escape then squeezed it and lit the gas coming out. It was very cool until I stopped squeezing the the flame got sucked into the jug. BOOM! My ears rang for 3 days.
Ever try Conestoga Toy Company Bangsite! stuff? Cannon and tanks etc that use CaCl. and you spark em off with a striker. Old school toys (dad had them in the 50s.) Still made. lots of fun till you have to clean them. I have my dads and my uncles. use them on the 4th of July, like dad did when he was around.