When discussing which products do and don’t work for beating drug tests, it is important to recognize that there has not been a great deal of research on the topic. Claims made by various products are rarely, if ever, tested by reliable sources.
Products that seem to show some successful outcomes are THC detox kits available for sale online. Some journalists at Vice performed a very rudimentary study, testing three THC cheating drinks. All three seemed to work, although it should be noted their test pool was a single subject using the products a single time (with one control test to make sure the risk of an error with the tests themselves was low).
Beyond this basic test, which only really shows that more research should be done on these products, it is difficult to make many positive claims about the products available to pass drug tests.