well if its a hair sample i think ur fucked, the thc stays in ur hair for 1-1.5inches and after that its doesnt show and its destroyed so if the hairs 1.5inches long it can still show, but dont qoute me on this but i think i read somewhere if you bleech your hair it will test clean... so bleech ur armpit hair blonde then black again (unles ur a weird arien then black then blonde) and as far as getting a piss test good luck and go for diloution, i doubt it will be unsupervised if u can get a piss test so dont hope for substitouin.