I've just been polishing some ali channel. I started ("ended up") with 2000 grit wet and dry, and from then on have used a really simple cotton mop (in an electric drill on a horizontal stand). On that I started with the equivalent of Solvol Autosol (paste in a tube), then Brasso and then "finally finished" with the red jewellers' polishing paste that came with a set of Dremel accessories. That was the order I used because I THOUGHT (only a guess mind) the above was in descending order of coarseness. Final final finishing was with a piece of soft dry clean cotton cloth by hand.
The result is OK and so far (finished about a week ago) there are no signs of the ali tarnishing.
As I say, the above was all guess work as I didn't want to invest in the fairly expensive polishing sets including various grades of mops and polishing media which I know are available from specialists. The above job is for the windscreen frame of a child's pedal car so I wasn't TOO particular, and for that use I think the result is good enough.
But if it was for something really important to be seen by critical "professionals" I would have gone more deeply into it and probably bought the proper gear.
Back to answering your original Q, I THINK (don't know for sure) that Brasso is a bit less coarse than Solvol Autosol and coarser than the Dremel polishing rouge, but that's purely guess work and I have no idea of the relevant "grit" number/s.
P.S. If you do use Brasso, do NOT do what I did and apply it to the mop! Apply it fairly thinly to the job and rub it in a bit first by hand. If you do it "my way" you end up with Brasso stains all over the wall, floor, and ceiling!!!!!!!!!