Gunpowder! Making it the old way, with a manure Wish List ...
Survivalists and gun enthusiasts today enjoy (well, maybe) making their own gunpowder. For the potassium nitrate, one recommended process is to put a lot of manure in a large drum with a drain, valve and filter screen installed at the bottom. Pee into it. Freely. Then add water for a total of about 300 gallons of yuck.