got evalution soon and i need to pass drug test

i got arrested about a month ago for public intoxication, under the influence, and resisting arrest. even though some of these are some bull shit charges i still have to go to my evalution which is part of my probation. i already took a drug test a month ago but you already know i smoked after that so i need help passing this drug test. i was thinking about putting some bleach in my piss but i was thinking that they might know, im not really sure though sense im taking my drug test at a hospital. so if you got any tips for me tell me because im going to need it. thanks