Milk thistle has no effect on THC. Drinking water days or weeks before the U/A is useless. THC is not water-soluble, its fat-soluble. THC is stored in the fat cells and remain there until the fat cells are burned for energy. You cannot "wash" or "flush" THC from the fat cells by drinking copius amounts of water. When fat cells burn, the THC metabolites are released back into the bloodstream, filtered by the kidneys and deposited in the bladder. The rate in which the THC metabolites are filtered from the bloodstream by the kidneys is unaffected by drinking copius amounts of water.
Drinking water is only good for the day of the U/A. It only serves to dilute the THC metabolite concentration that is present in the bladder to where the urine sample can register below the cutoff thresholds of the drug screen. The phenomena is only temporary. Once all of the water consumed had already been urinated out, a "dirty" donor would resume testing positive for THC.

Dilution techniques can backfire if the THC metabolite concentration in the bladder is too high. For most longtime daily users, it would be virtually impossible to dilute that concentraion enough without overdiluting and sending up the red flags at the lab.
Burnt Toast Reviewed by Burnt Toast on . Im lost - drug test this month Hi everyone. I have done some reading on this forum and I cannot come to a decent conclusion on detoxing my body in time for Drug test. My test is on the 31st January (this month) I smoke between a £10 or £20 of bud every day (thats 1.4 gram for £10 or 2.8 gram for £20) I know thats expensive but thats what everyone gives round here. I smoke for various reasons - the buzz, to feel normal (i feel im addicted and get anxious when i havn't had a decent joint) Rating: 5