hmm from what i heard the only thing that helps to detox is a zinc supplement - but its all just snake-oil, dude...

your chances of coming up + for THC in a piss-test diminish steadily after the first couple of weeks, and if you've been flushing your system consistently with water, vitamins and exercise the window shrinks drastically thereafter. piss-tests have short windows (up to a month), hair-samples tests can come up + for up to 3 months, and there are other, specialized tests using fatty liver deposits that can show usage after even a year - but those are very expensive and used in serious cases only, like murder trials and stuff...

had a mate in uk who came up + on a work-mandated piss-test after only 1 week clean - but he insisted on a retest saying that his diabetes caused a false + (total st0ner bullshit, but he does have diabetes and it has been known to happen) so they retested a week later and he came up clean