I mean brain states being caused by other brain states--we have a lot of evidence for that because we can intervene. There isn't much room for a nonphysical consciousness to intervene on the physical manifestation of brain states. As I said last time, not all the details are worked out, so there's a little bit of room, but it's all looking pretty darn physical so far. And experiments sure make it look like consciousness is causal, though again, there's still a little bit of room for p-zombies. We don't have every bit worked out in full. We only have pieces, a lot of examples, and haven't found anything weird.

How do we know that Jim Morrison is a real human rather than an alien shapeshifter? How do we know that Dwayne Johnson isn't actually a bunch of magic squirrels in a suit? Have you checked? There's not a single demonstration of every single human on the face of the earth actually being a human.

Some cars are powered by gasoline, some by batteries, and some by wishes granted by genies, maybe? Have you checked? There's not a single demonstration of every car on the face of the earth not being powered by genie wishes.

But induction works pretty well. We don't bother with that stuff because that's not how the regularity of the universe seems to work. So "you didn't figure it all out" in no way supports the idea that "and secretly hidden in here is something that is utterly unlike how things normally work".

So, consequently, I reject your proof by incredulity; while keeping open the possibility that it might possibly be non-computational, since all the best evidence is that it is, I would not be the tiniest bit surprised if waterpipe-brain was conscious.

That you have poor imagination in that regard says a lot more about your imagination than about the nature of reality.