Although if you grow organically, you are using poop in your grow. I have heard about using piss as a deterrent on an out-door grow to keep animals away, the scent may help in getting rid of deer and so fourth. While urine is high in Nitrogen, even if the urine doesn't effect the buds negatively, I'd have a hard time smoking nugs that were ferted with piss.
You won't find an OMRI seal on pee, either.
Take a crap in a sunny place in your yard. Bury it and wait a few days. When no plant grows you’ll have your answer. lol
I surely would not piss on my plants.
Peace