CLEAN PISS??HELP

well i have somehting like prohbation... JCC... it requires me to get drug tested once a month and bring in the report... well im not going to trust DILUTING(i smoked on friday and i drug tested my self yesterday.. i drank 1 and a half bottles of water and the bottle was pretty big like a foot tall and pretty wide i forget the exact amount), so what should i do with clean piss..? i can get it.. but how should i bring it in they wont search my croch but i was worried about temp.. THANKS. eggynogg..