Quote Originally Posted by smaughazard
In ancient times the process of fulling involved using the feet to wash the material in a vessel of stale human urine (a rich source of ammonia). Priests' urine was especially valued for this task. (One would hope that this was followed by a thorough washing.)
I wouldn't bet on a "thorough washing."

Urine was once highly prized as a cleansing agent - for teeth, among other things.

Romans used urine as toothpaste and a rinse.

It's not as big a deal as people today would think - barring any urinary tract infections, urine is as close to sterile as anything. (And if you believe Wikipedia, it can be used as a mild antiseptic.)