Someone who invests in something like a cleanse knows they don't feel as good as they'd like. What happens is that they not only get the product but, for a while, they actually try to eat better (for a while). I wonder which one is helping? This is similarly true for so many bodybuilding supplements that are worthless but gain popularity. Someone isn't satisfied with their progress, so they buy the supplement. At that moment, they are motivated so they make the investment; but they also dial up the training and clean up the diet. They start to improve, and give the credit to the worthless supplement.
Ah the placebo effect, and I can remember a time when "science" was saying that AAS were not effective but because athletes believed they worked that it was the placebo effect that was the cause of the gains we made in our given sports. However now AAS has far to much real science backing up its effectiveness, but this of course is not the case with most supplements. Therefore I suggest that before one jumps on a supplement bandwagon that they get their training in order, make solid changes to their diet to create an anabolic environment for growth as well as just better overall health. And once this is accomplished then try out said supplement for a period of time. Once finished the supplement cycle then see if you noticed any results when on or when you came off.
I've tried this with every supplement I currently use and as such I only use what works and not those supplements that don't (no matter how good/persuasive the advertising may be).