i would juice the heck out of an acre of grass before i would try urine.
that said, there is more to this than meets the eye, or tongue as it were.
what passes through the kidneys from the blood is EXACTLY what the body has seen fit to put in the blood. it is also what has gotten into the blood regardless of what the body thought of it. i would say the only way ut would be good is if your blood were already clean. and if that were the case, you wouldnt be sick. so there.