In the 1920s, Billy Mitchell advocated for the building of bomber aircraft but the military considered bomber aircraft to be "unproven".
The problem is that the military also was not prepared to conduct legitimate testing to discover whether Mitchell was incorrect or not.
Once something is tested and found inadequate to the task, then and only then, is it appropriate to begin attacking it.
Just as the medical community resisted for years the idea that ulcers are the result of an infection because that idea was "unproven" and yet showed no interest in testing it in order to DISPROVE it, so also some of what is going on now in the medical field is unscientific.
Instead of discussing whether or not something is unproven, we need to discuss whether tests have shown it to be disproven. Once it is disproven, then you can truly Fact Check it, but it is not "fact checking" to merely state that something is unproven because all treatments are unproven until they are tested.
A religious text admonished its readers to not dismiss something until they had put it to the test:
"Test all things; hold fast that which is good"