You can put an inch or so of cow shit in the bottom of a shoe box, a bit of dry ice and a half cup or so of denatured alcohol, then tape it shut and put an igniter (I'd usually use a firecracker stuck half way through the lid with the fuse against a stick of inscense for a timer) on it. When it goes off, there's a tremenous boom and a scattering of fecal matter everywhere! Great for Pep Rallies!
