So, drink it every hour on the hour for 48 hours before the drug test. This should sufficiently loosen your digestive system enough to produce explosive diarrhea, and reinforce the lesson that no matter what you try, you cannot cleanse illegal or even legal (although illegally used) prescription drugs from your system.
All that will clear your system of the foolishness in which you have engaged is time. Roughly thirty days of it.
Get clean, and try again. If the drug test you mention is for conditional release (parole, probation), your best bet is to throw yourself on the mercy of your supervising officer (PO), and hope he does not violate you.