Dilution does not work on them, but you've got 2 chances before you are told not to try again for a year. My buddy took the UrineLuck(sp?) and passed alright, I failed because my piss was neon green & diluted. Then Afghanistan happened so I said f* it, there's less lethal ways to get a paycheck...Good luck. Oh & dude's right about the time & excercise. Hit the sauna, jog a few miles a day with a trash bag over your torso to get the sweat pouring, etc...<--from my recruiter. Ask your recruiter, no doubt he's come across a few potheads...