Do Bajoran religious officials go by anything when they say somebody's p'ah is strong or are they just saying what they know will encourage the person's faith?
I'm quite sure it's the latter. In one episode ("In The Hands of the Prophets") Vedek Bareil even calls the whole pagh
detection with fingers an "archaic ritual" and that one of his life's purposes was to break with it. So I really doubt that it was anything more than a mere superstitious practice and I'm pretty sure that there was no real in-universe science behind pagh
detection – even with their gods, the prophets, being real alien entities. That's what I took from it, however.