Nose grease and an old, soft clean handkerchief work for me. I only use my low speed buffer for the bits. But, pretty pipes aren't that high on my list of needs.
If I was to buff my pipes mechanically I'd use a low speed buffer and clean, soft wheels. I'd apply the wax and allow to harden before taking it to the wheel. Compounds are usually reserved for polishing metals and sharpening edges, they remove material, even jeweler's rouge can remove more than you want if not careful. Grinders, even variable speed, are for... grinding. Soft buffing wheels on a low speed buffer is the best way to go, unless you are extremely skilled and experience3d. Oh! And watch for flying pipes. It will happen at least once no matter what you use, buffer or grinder. They will fly farther and faster with a grinder.
I'd recommend wax, nose?, and a soft, clean cloth.