All those magic cleansing products are a scam. Of course they want you to drink a lot of water - they work because of the water thats required to be consumed with them. They are nothing but overpriced diluters. They work by temporarily diluting the THCA concentration thats present in the bladder - enough to fool the THC screen. The same thing can be accomplished for $$$ less by following the guidelines in the Dilution sticky thread.

And more water is not better. Drinking more water than what is recommended in the Dilution guidelines increases the chance of the sample coming back too-diluted.

Niacin is a myth. It does nothing to pass a U/A. As with the magic cleansing potions, its the water consumption and not the niacin itself, that allowed those people to test negative.

There is no product that can permanently rid the body of THC. Only time and exercise can do this.