I used to smoke weed, and I drank one of those $50 drinks and it worked. The thing is the test didn't come back clean, it came back as inconclusive. I think the tests themselves are costly to employers but they do it for insurance and liability reasons and more so as long as it doesn't come back as "positive" they can't just probe at you assuming it will happen...
Let me clarify:
Where I'm from the employers spend more than 20 dollars for a testing kit, and any masking agents\cleansers won't pass the test.
they are too sensitive for that.
I myself used a brand of fake urine to pass the only drug test I've ever taken. I watched the results unfold before my eyes. Basically if the line shows up, that drug is not in your system. The THC line was very, very, VERY faint... and the nurse looked at me cock eyed but said it was enough for a pass.
BTW if you test "inconclusive" for most employers in my region you will be asked to re-test with a lot less privacy this time around.
Sure-fire way to pass a drug test:
a) clean up with plenty of time before hand. common sense: smoke pot again after you pass. it's all good, if you have to quit for 2 months you'll get stupid high when you start smoking again..
b) use a clean friends urine and don't fuck it up. start a pocket handwarmer 1 hour before hand and tape it around a plastic bottle or vial small enough to fit into your underwear. place it under your balls.