Wet sanding is way easier than dry sanding, so you'll do the job faster and better. But it's still a lot of work.
I think 500 grit is too fine for paint removal. It makes the job too hard for my lazy butt. I'd start with something more coarse, like maybe 200. But be gentle so you don't scratch it up too badly. Then switch to 500 (or even more) to get a nice surface for painting.
Curt