To clean nickel guns, I use Prolix. It works great and it is safe for use on nickel finishes. I polish with Flitz, and the use Reniassance Wax to protect the finish. As mentioned Mothers Max polish is good, any good carnauba wax will work. For me, Flitz and Reniassance Wax work the best, but that is what I am used to using. Soft cloth and do not press hard when using ANY polish. Any polish is abrasive.