Unfortunetely, hair tests are hard to beat. Since THC is stored inside the follicle..........there is nothing you can use to "wash" it out of your hair. Your only hope is to mask the hair they use.................and as of yet, there is really nothing that will help you pass. Nexxus "Aloe Rid" is sold in salons, and high end hair care shops................this is the only product I have heard of that "has worked" but that is debatable.