Air Pressure as Gravity Query

Hello!
One aspect to FET I've seen used occasionally, is the idea of explaining gravity as caused simply by air pressure. (This isn't about denpressure, that's certainly one subset, but it's not the only one. I more or less understand denpressure, so I'm more interested in the rest).

My main question is, what causes air pressure to act in a certain direction?
If it's just a law, why is air pressure required; surely we'd all be moving that direction then regardless?
If it isn't a law, what is it?

I'm not interested in having a huge debate, I just want to know what the answer to the question is. (If you have a different explanation for gravity, I'm interested in hearing it, but not in this thread. As it is I more or less know Scepti's denpressure, JRowe's aether, UA, the mass-to-mass attraction of RET and IET, and some of Sandokhan's magnetism-thing... Don't know how many more explanations there are).

Thank you!

Scepti says air particles form a stack, with the most dense particles sinking to the bottom while less dense particles rise to the top. Think of a kind of buoyancy.

You have explained this to others using an analogy involving a swimming pool if memory serves.

Scepti says air particles form a stack, with the most dense particles sinking to the bottom while less dense particles rise to the top. Think of a kind of buoyancy.

You have explained this to others using an analogy involving a swimming pool if memory serves.

I know. Like I said, I understand denpressure, but other people use the air pressure model.
The denpressure form of the model relies on a different kind of matter and molecular structure, and it's very specific about that. Not everyone accepts that model though: there are some air pressure models which don't rely on the same principles as denpressure. It's those I'm asking about.
Denpressure answers the question with the appeal to an buoyancy-like force, yes, but I'm asking about other models. If they rely on the same, then fine, but that's not a conclusion I can reach without more input.

Charming Anarchist subscribes to the air pressure model, I would enjoy seeing him share some information on it.