There's another one around somewhere of some rocket scientists mixing ammonia and alcohol for the same effect. Well, almost the same... instead of pool water going all over the place, I imagine it was one of the kid's hands that was spewing blood all over the place when it blew up in his hand. I recently pressurized an empty 2 liter bottle at 100psi and shot it through a piece of plywood. (oops!) And, I've seen a photo somewhere recently on 2liter bottle rocke sites that showed a shirt ripped to shreds - the shirt had covered a bottle shortly before it exploded.