So.
We used to take soda cans, cut the tops and bottoms completely off with a standard can opener, we’d tape about five or six of them together with electrical tape and for the last can we would puncture a small hole in the bottom and on the top would use the pointed end of the opener to create openings without cutting the entire top off.
Now these cans were the perfect size for a tennis ball.
We would squirt lighter fluid in the small hole in the bottom, drop in a tennis ball that was soaked in lighter fluid and light the bottom.
And well, it was like a cannon that shot a flaming tennis ball.
Awesome !!!!!
Tennis ball cannons had a better rate of fire if you used lacquer thinner. Just make sure it’s out before re-loading if you enjoy having eyebrows.