An answer that points out that there is no evidence that some (quack) cure X works, doesn't need to be supported by references. Obviously, the burden of proof that X works should be on anyone making the claim that it actually does work. A statement that there are no peer reviewed articles about X's efficacy should be sufficient. Otherwise, people promoting quack treatments can just ask suggestive questions here, without there being any critical response here as such a response would violate the requirement of references when there hasn't been any research done to see if X works (which is usually the case).
Now an OP may not have the intention of promoting quack cures here, it may well be a legitimate question. But a lack of a response that makes clear where the burden of proof lies, will have the effect of people reading such questions and answers posted here being misled about such quack cures.