How accurate is the swab test for marijuana?

in my experience, not very.

i took one as a pre-employment requirement, after smoking heavily for 3 days during a going away party before i moved. i wasn't aware at the time that a test would be required so i was freaking out. the company did a swab test, and i passed! i quit, and a month later, went back to the same company. this time, i smoked a bowl on the way to the test.....and passed again.

i do smoke cigarettes, and from what I've gathered, brushing your teeth, mouthwash, smoking a cig, Chewing Gum, etc (essentially have anything in your mouth shortly before the test, in order to throw off the pH balance, will let you pass.) I've also known people that had serious amounts of xanax, hydrocodone, and oxycodone in their systems that passed as well.