Me again!! He failed the drug test.... We have noticed that the best thing to do to pass is not to smoke. Nothing is 100%, except that whole thing with the tubing and the shut off valve looks like it would work, but I'm sure even those have failed also... Damn, this is depressing ... I just don't understand why it's not just legalized!!! I really feel the pee test is very Nosey, the saliva test is only from the last week or two isn't it? I think that would make more sense. It's not fair that if you smoke on your own time you can't get keep (or get) a good job. It doesn't mean you go to work High!!! That is so unfair, not that the law will change just cause "I" think it should, it just sucks. We followed the ZyDot instructions and it didn't pull thru, N2 has the BEST way, with a substitute in a rubber. DON'T USE ZYDOT unless you really don't give a shit what your results are!!!