This a 100% full proof way to beat your test. I have used it many times for both parole and job piss tests. To start off the longer you abstain from a drug the easier it is to pass the test I would say at least 24 hours. So here's what you want to do about three or four hours before your test start drinking water nothing else. The amount of water you drink is determined by your weight I am 5" 7 and 130 pounds and I drink about forty or fifty OZ of water. You drink all the water over a hours time frame and keep drinking water until the test. You will know when your piss is clean because it turns clear it basally takes all the urine out of your body and you just piss water. I know that's not scientifically correct but I can't explain it another way. After your piss is clear keep drinking water and piss twice before the test and your good. You will come up diluted and probably have to piss again at some point but it will buy you time until your clean