How to P a Hair Follicle Test?

My boyfriend has a really great job opportunity coming his way, but he's going to have to take a hair follicle test to get into the company. He has about a month till the test and has already quit smoking pot and the such. Does anybody know how to p the hair test, products you can use that actually work, natural ways to cleanse the follicle, ect??? Please help... this is an awesome job!!