Yes the U/A is job related but the problem with substitution is trying to keep the right temperature. I've passed several drug exams before without ever using substitution. In the pass I have done something similar N2's dilution method but instead of taking vitamin B pills, I drink powerade. Instead of gatorade, i drink powerade because powerade has a lot of B vitamins in it. I also drink vitamin water because it has B vitamins as well. I also drink one beer and one bacardi silver. And even though some people oppose certo, I still use it because it doesn't hurt to try it. I've never failed using certo. It seems as though the drug exams when I didn't take certo were the times I failed. If I pass the exam tomorrow, I'll share my method with u all