I've had friends pass using detox drinks like the ones you can find at most head shops. Also, I have some other ones that swear by using sure-jell (fruit pectin), one even claiming to having smoked the morning of the test and then passing using it. But the best advice i can give is just avoid fatty foods, work out and sweat a lot, drink lots of water and then just hope for the best. Using something to detox can't hurt though, its worth a shot. Good luck.