Don't mix bleach in with your urine if you're testing with anyone who's half serious. They test for "adulturants" added to the mix, e.g. bleach, vinegar, etc. Also be careful with the water dilution method because most lab tests will make sure you have reasonable creatine levels to catch people who are trying to drink water until they piss... water.

Like someone else on this thread says, use one of those "herbal clean" products from your local GNC. I've used the pills with success before, though I don't know about the drinks they sell. Good luck.