have you ever blown anything up, reg?
I bet reg had an inflatable banana back in the day...
Nah, didn't even have a short lived inflatable robin....although I wish I did now.
When I were a kid, we used to make cap bombs....these consisted of 2 bolts acquired from the Works, screwed partially into a nut....the void between was then fill with caps, which I assume you can still buy...but if you can't were a bit like the explosive in a cracker..
The skill was in loading the right amount of material and gauging the right amount of space needed....you then dropped the device from a height and got a small percusive explosion.