The assertion is, to be more precise, that the proponent being able to conceive of p-zombies means that physicalism is false. "Physicalism is false" is very much "anything like" dualism. It's still p-zombies therefore magic.

I'm speaking here strictly of the Chalmers formulation, not necessarily variants. Chalmers endorses panpsychism (a philosophical version of animism) rather than strict Cartesian dualism per se, but this is splitting hairs.