As a heuristic, I suspect ignoring things ignored by most scientists will actually work pretty well for you. Its not an unreasonable assumption to say that "given no other information, the majority of scientists dismissing a subject lowers my probability that that subject has any grounding".
If you don't have any information then that might be true. Usually you however do have some information.
Note that we essentially do this for all science, in that we tend to accept the scientific consensus.
That's only true for fields that are studied enough for there to be an evidence based scientific consensus.
It would be a powerful tool to be able to dismiss fringe phenomena, prior to empirical investigation, on firm epistemological ground.
Thus I have elaborated on the possibility of doing so using Bayes, and this is my result:
Using Bayes to dismiss fringe phenomena
What do you think of it?