My dad once confided to me “an old farmers trick”, namely to pee on your hands to alleviate blistering. I’m sure it works great.
It can be soothing for itching due to insect bites and stuff. As I understand, it’s a remedy for jellyfish stings, though I have no personal experience with that.
Internal use—not for me, or most Americans I suspect. But I understand its a popular practice in some Asian countries.
There was a lot of discussion(rather more than I would have liked) of urine drinking in the memoir Yoga Bitch. I forget the authors name offhand.