Your best bet is to just drink a lot of water. Make sure your running clear when you go for the test, collect mid stream. This is the best way to insure your test will go well. Trace amounts are acceptable on most tests, you're just looking to get it diluted down.
A good way to pass a drug test is vinegar pickle juice is vinegar drink like 2-3 jars a day till your drug test and if you have the money there are energy drinks that mask the THC in weed so your urine looks clean
NO NO NO .. When will you people waken up and smell the coffee ? You take the drug .... So be prepared to accept the consequences .