Yes. My friend swares by it and has used multiple occasions for parents and for the court(was on probation). He suggests you stop smoking weed for two days before you drink the qcarbo...and you should be clean after you pee it all out.
No. How these things ACTUALLY WORK, and not the "super magic herbal essence" way the labels claim they work, is by diluting your urine. (Remember, Spice is supposed to be some super magic herbal...
They worked for me, but I also stopped smoking for 9 days before the test. So was it abstinence, or the drink, or both? I don't know. It's worth a try, especially if you cannot postpone the test...