bleach, niacin, etc., are 'masking agents' specifically looked for, by most modern drug-tests ... if it is spotted, you will flunk, and be required to re-take the test while being watched, to make sure you don't attempt it again ... either smoke dope, or lose your job, because these drugtests are much more precise than they used to be, and the various 'flushes' and commercial concoctions are a waste of money ... :smokin: