#1- when is the last time u used substance
#2- when is the test date
there is nothing at all you can buy in a box that you can use to stump the test. The drug testing industry is major $$$$ industry - every product out there making bogus bs claims the laboratories are well aware of.
if it is NADA-5 piss test, you *may* succesfully pass given enough time, depending on volume of substance used.