Yes, 600 is great for most cleaning/sanding, the higher you go on the following grits, the smaller the scratch pattern and the better the final shine.

Follow 600 with 1,000 and even go to 1,500 and 2,000. The higher you go in grits the less time you will need sanding, as the scratches get finer. You can get a set of Micro Mesh paper, from most hobby stores, that go to 12K and/or foam 3X4 pads for around $20, that finish, to the naked eye as a polished finish. They do last a long time, then go to your metal polish for a very mirror finish.

We all have our own preferred finish polish, (I have a cabinet full). I use Mothers to polish and build a finish, then do a finale polish with MAAS, (because it is expensive and hard to find locally, though lately, my local Ace Hardware has been carrying it), just using a couple dabs with paper towels and buffing with Micro Fiber.

Personally, unless the etch is pristine, I buff it off. Geezer has a good post in the Workshop on darkening and trying to save an etch.