Okay.... I have finally been accepted into the community so I just want to let everyone interested know that subbing works. I just passed my third drug test by subbing synthetic urine, twice with ultra kleen ultra pure and this last time with BC Entities field kit. I am here to assure you that if you follow the directions and get the temperature right you will pass using this method. I just got my results today and I am now going to be making the big bucks ... so trust me when I say you can't go wrong with subbing ... I am an extremely happy camper