coffee, tea or pee?
There's lots of urban mythology about urine being medically restorative...it's a load of bunk. Pee is not sterile and if the person has std's, hepatitus or a urinary tract infection and you have broken skin, it's a huge safety risk. However as long as everyone's healthy, it's a perfectly safe activity...just shower well afterwords.
As far as drinking the stuff's concerned, most guys i know simply like to have their mouths overflowing with it...or streamed hard on their cocks while they masturbate...and although i haven't read any medical studies, it seems to me that stomach acids would take care of urine quite nicely if you swallowed.
Also, keep watersports in the tub...clean-up's so much easier.