If you have real pitting then a clay bar won't do you any good - they remove bonded surface contaminants only. Rubbing compound is generally a bad idea unless you know what you're doing as it will usually scuff the paint up pretty badly. If you know how to fix that then it's sort of a non issue, but most people don't and end up with a mess. Wet sanding would be akin to rubbing compound except the potential for disaster is far, far greater. You need a rotary buffer to completely pull the sanding marks out of the paint.

Do you have any pictures of the pitting? Sometimes short of repaint there isn't much you can do for some defects.