That shower one, is that a firecracker? and wouldnt the flame go out because of water? . Thats a fucked up stunt he pulled.
fuse is water proof.. http://www.pyrocreations.com/inc/sdetail/530 good ones will not even go out completely submerged..
its a chemical reaction. some chemicals in water become more flammable like lithium.. producing highly flammable hydrogen gas...