Ew!
Although it reminds me of a lot of fun had with compressed gas tanks and bigger bottles when I was a kid.
Used to make this plasticised composition of potassium or sodium chlorate, powdered sugar, a little bit of salt (to slow the burn rate and make it an incendiary rather than explosive, the salt is noncombustible and phlegmatizes the mixture), wax, some petroleum jelly and when I had any, some potassium nitrate, and ideally, aluminium, magnesium, zinc or other reasonably reactive metal powder.
I'd strap blocks of it, cast into shape (since it could be melted in hot water baths and then melt-casted into molds for the application at hand) around a drinking straw filled with a sodium nitrate/sugar mixture with a little mixed potassium permanganate and metal powder sealed into the bottom end buried in the incendiary block as an igniter; to the likes of big propane or butane tanks, take them into the middle of nowhere, or where there was the likes of an abandoned building to bugger about with, light the fuse and either run like hell or jump out of the nearest window.
Oh boy, those things didn't half go up like a bloody rocket. And the bang was terrific. Under an abandoned car was a great one too, watching the detonation send gouts of flame blasting out from under the bucking, shaking car as if it were a dragon spitting fire.
