I wouldn't worry too much about the listerine dude. I am highly skeptical that this works.
Most of the stuff I've read where listerine works is in cases where they have smoked Kush, Salvia or taken some sort of drug that has only (relatively) recently become illegal.
If the tester isn't paying for a very up-to-date and super accurate tests, then you will pass.
But if they are looking for mephadrone, then there's little that you can do. Luckily Mcat is pretty new so you should be ok.
Also doesn't Listerine contain alcohol? How is that gonna look on your test if it shows a reading that looks like you turned up to a drug test wasted??
