I apply fresh urine on my face practically every night.
I don't really notice it affecting acne, but it does soften the skin and make it smoother.
For acne, I apply Tea Tree Oil on my feet every day several times a day. The oil permeates through my skin, circulates through the bloodstream, and the anti-bacterial/anti-fungal properties really do a number on clearing out my skin. It's the best anti-zit treatment I've ever used.