Drug test are performed on blood, hair, or urine in order to confirm presence or absence of drug in human body. Before going head and talk about cleansing of body before drug test first I want to tell about how drug is stored in body, in form of THC, chemicals and metabolites they get stored in fat cells. Cranberry juice is not so useful to pass drug test as it cannot clean the metabolites and THC from your body but only can act as diuretic and make you pee like mad, change pH of your urine. This juice cannot make the drug flush out but can act as cleanser to your body and treat many diseases like, urinary tract infection, cleaning liver, kidney stones, diabetes. The only thing you can do 24hrs before drug test is to drink lots of water, usage of fake urine, drinking vinegar which are not so accurate but may help you to pass drug test. If you wanted to pass drug test and you know about the drug test long ago then you have many remedies to do and pass drug test by avoiding weed, drinking lots of water, keeping yours self on diet and cut off THC, chemicals and metabolites stored in fat, eating greens, drinking lemon juice, avoiding junk and eating fiber can help you and passing of drug test will be definitely successful. Cranberry may not help or be a good idea to drink it before 24 hours but using artificial urine cleansers, drinking water, taking b-complex multivitamin, taking aspirin (4-6 hours before test), before giving your sample at least pee twice before and using detoxifying agents will also be helpful. I read this to learn how to pass a drug test.