Use the Billet to remove any scratches that are left after using Mag & Alum polish. It's a lot finer polish and it's to get even more shine. Don't use a terry towel when applying it, use a nylex glove (I think that's how it's spelt? you should be able to find it with all the domestic cleaning chemicals, gloves etc). When you use the glove it'll prevent marring caused by the terry towel.

 

I used a polishing towel (which seemed a lot finer than a terry), when I first applied Mother's Billet. Oops.

 

Applied Mag & Aluminum Polish with a terry, but this time instead of removing it with another terry.....I buffed it off with a polishing mit (I believe it's lambskin). Looks even better now.