I think it's like all these things. P, to me at least, is a symptom not a condition in its own right. It is merely the outward manifestation of a number of different conditions.
For instance, I have plaque P, which looks nothing like some other people's plaque p.
I don't think, per se, there is a treatment for p. I think there are treatments for the underlying conditions that cause our skin to erupt.
I have absolutely no doubt that candida infection is responsible for some of these cases. This is why there is so much idiosyncracy with the various treatments - what works for one doesn't work for another.
Likewise, other people's will be strep infection etc.
The common link is the hyperactive immune response - any number of things could cause it.
The tricky bit is discovering and understanding the route cause of our own P.
As it stands, this can only be a trial and error process - from my point of view, it has got to be worth a try.
If this doesn't work, I wont give up; I will merely move onto the next util I find the route cause for me (whether that takes 1 year or 40 years, it's got to be better than looking and feeling like a leper)