sorry David but I think you`re on the wrong track....
urine contains ureea along with sooo many toxines....
ureea is made easily in pharmacies ( chemical, syntetical way; without any urine ! - it looks like salt/sugar cristals) and it can be mixed with other stuff - like glicerine for instance; i used it for one year and it worked just fine; my skin was no longer scaly; only reddish.
anyone can make his own urea based cream .......without drinking urine....