Drink lots of water so you piss as many times as possible and drink cranberry juice as well the more you piss the better then go to gnc and buy the detox drink called qcarb20clear or qcarb32 the 32 is bigger but doesnt come with the multivitimans and they are very important w/o them they can tell you took the drink , then 4 hrs before the test take 4 asprin and only asprin not tylenol , then 1-1:30 hrs before you have to piss drink the qcarb for the best results ,after you drink it piss like 2-3 more times this works on even the strictest probation tests trust me I know this is not 100percent but this is the best you are going too be able too do w/o using clean piss most places they watch you thou if they don't tape clean piss between your legs close to your privates you do this to keep it body your body temperature because they look for that goodluck
There are plenty of masking products sold online on sites like www.passdrugtest.com GNC also sells them. Not sure if they work but they claim to.