If I were to "hypothetically" be subject to random piss testing, here is what i would "hypothetically" do. First, pound water like a mother fucker. Second, Pee. Repeat first and second steps until pee is crystal clear. Next, pray to whatever higher power you beleive in. Then, I would fill an eye dropper with some liquid bleach, or put powdered bleach (clorox) under a fingernail and put that in my sample cup along with my crystal clear piss. I make no guarantees this will work for you but *fingers crossed, knock on wood* been good to me so far...

Hope this helps