Yes, fat cells store THC. An overweight smoker that has stopped for more than 30 days could test positive if they perform an activity that causes them to start burning their fat stores. I don't know which detox is best, but the 24 hr ones just mask the presence of THC by putting so many nutrients in your body that the screen cannot find the THC it's looking for. I have always just stopped smoking. It sucks, but it is very doable for me. Keep me updated and good luck!:stoned: