> The physical processes of pain (ie. the electricity) can be observed scientifically, but the "sensation" of pain (to use your word from before) cannot.
You state this as though it's a given, but it's not. You're assuming Dualism. So, of course you end up with Dualism.
> But it is the "sensation" of pain that gives it its moral significance, otherwise inflicting pain would be no different morally than flipping on the switch to an electrical circuit.
This is a silly over-simplification. Complexity matters. The patterns of electro-chemical reactions that occur when I inflict pain on another human cause that human to emote in a way that I can relate to because of the electro-chemical reactions that have been happening in me and those around me since before my birth. So what?
It's in no way comparable to flipping a light switch, except in the largely irrelevant detail that electricity was part of each system.
The fact that an incredibly complex system consisting of individuals, language, and society should yield different results from three pieces of metal and some current shouldn't be the least bit surprising, and is not a reasonable argument for dualism, or p-zombies.
Here's my take on the p-zombie "problem". We can say all kinds of shit, but it doesn't have to make sense. For example I can say "This table is also an electron". That's a sentence. It evokes some kind of imagery, but it's utter nonsense. It doesn't point out some deep mystery about tables or electrons. It's just nonsense.