I have a buddy that bought piss on www.passyourdrugtest.com. Use this method if your system is too dirty to clean. Fortune500 companies don't pad people down for the same reason they don't do hair tests-if they were that strict then they would realize that a HUGE % of their workforce gets hi. If you are not a regular smoker and you have a high metabolism then you might have enough time to cleanse your system rather than submitting fake piss. To do this exercise(cardio) and drink lots of cranberry juice. Niacin also help speed up metabolism. Also switch to a high fiber diet because fiber redirects the THC metabolites to the colon(you poop out the THC). And the day of the test, dilute your system by drinking lots water. Drug test look for a ratio of a certain amount of THC to water. If you drink enough water the ratio will go below the flunking point. Here the GNC products(which are mostly creatine) may help because they can make your urine yellow even after dinking a gallon of water-creatine does that. When you submit urine thats pure H20, the testing people know whats up(they can't say that you flunked it, but they know that you tried to beat it and that can be just as bad. GNC products don't clean your urine, but they basically confuse the test people so you end up getting away with it. I did a paper on this in undergrad, and I've been there. And don't buy anything from a hitimes ad.