I've used both Mothers and Flitz and the Mother's polishing ball and the Flitz polishing ball. I like the Flitz products better. Initially, I polished and polished and they never looked that good. Finally....I realized what I was doing wrong. I was using waaaaay to much polish. Once I got it figured out, I found that I used about a thimble full of polish per wheel.
You just want to put on a small amount and buff until the wheel starts to shine. If you end up with a lot of black residue, you're using too much polish.
Once I got the wheels into good shape, it would only take 20-30 minutes per wheel. Once I was done, I kept them covered when not in use. Covering them extends the life of the polishing by 10 fold.
They make a tool with a rubber tip that easily removes the lug nut caps (Camping World), making it easier to clean/polish around the lug nuts.