Don't listen to all that B.S. The only way to pass a drug test is to stay clean. There are many inexpensive and expensive things you can buy (and philosophies on the subject you could listen to)- but they DO NOT WORK. As a matter of fact, most drug-testers will look for the ingredients of these homemade and store-bought remedies when examining the content of the urine sample, and, if they find any, your test will automatically be considered "dirty" just for having any of these things in it....
Even drinking more water (to dilute your urine) will likely cause your sample to be considered "tampered with" and therefore "dirty". Anything that changes the PH balance, too, will have this effect. My advice to you is to stay clean (I know it's easier said than done) if you can. And if you can't, well, it takes anywhere from a week to 30 days to clear your system of pot, and 7 days to 2 weeks for meth. Alcohol clears the system much faster. Good luck!
Source(s):
I used to have to submit to drug testing by court order.