alright, im not sure how many of you have heard about this before, but some people i know do it, and they say it works like a charm everytime.
go to walmart and go to the camping section. they have stuff called portable aqua. all they are are tablets you put in a gallon jug of water. drink that gallon jug within like an hour and a half, and then piss a couple times.
usually, as soon as that portable aqua hits your system, it cleans everything in it... cleaning out the bad.
try it and buy your own tester to give it a shot before, but it's worked for them 100% of the time.