When people talk about their consciousness, they communicate using things like their mouths and hands. Mouths and hands are physical.

Or do you belong to the school of "People talk about their consciousness not because of their consciousness, but from an entirely different chain of events that just happens to be accidentally correct"?

Not the OP, but consider the p-zombie world thought experiment: Chalmers would have us believe that we would still be having precisely this conversation about qualia, even if qualia were impossible in such a world, and no human had ever had a true subjective experience. The concept of qualia would still somehow have been invented and triggered precisely the same centuries of disagreement that we have seen.

This is as equally inconceivable as p-zombies are conceivable (to some), therefore I can only conclude that there is some fatal flaw in the p-zombie argument, and so I dismiss the conceivability of p-zombies. Thus, the presence of consciousness must somehow be behaviourally distinguishable.