[Hardastarboard]

I read somewhere that they really did use urine to tan hides, so that an intrepid young man in a leather coat, going to his girlfriend's house, took a serious risk when it rained that the smell would be released. :-)

I also read that they used urine in the time of Napoleon to "corn" black powder, since the individual ingredients, mixed together, would settle out over a long march, and wouldn't burn properly. I believe this was partly because urine contains nitrates. YMMV

[Vaquero]

Potassium nitrate, the oxidizer in black powder was originally gotten from farm animal waste ( they hit a jackpot if they found a cave full of bat guano). I knew they corned BP with a liquid and then dried it in the sun then broke it up in different size grades to get better performance.

Didn’t know they used urine for Corning

[golux]

Urine is still used to tan hides. Survivalists do it... Inuit do it... But I am highly skeptical of some of these “origins.”