The saliva drug test is a very common form of drug testing. If you are asked to take a saliva drug test, the best way to detox and prepare is drinking plain water and perspiring. Especially for those with high toxin levels and THC users. Toxins are stored in your fatty tissue which is your skin. Drinking water and sweating is the only way to get clean or lower your drug metabolite count making it easier to mask whatever toxins are left. How fast you get clean depends on your fatty tissue count, speed of your metabolism, strength and amount of toxins ingested and for how long the toxins were ingested.Products to Pass a Saliva Swab Drug Test.