Clearcoats and metallics usually don't play nice with eachother. I skip the clearcoat on metallic surfaces whenever possible.
Rub-n-buff is a particularly fragile treatment. As far as I've been able to tell, it never completely dries, so it wears away with friction. Still, it is one of the nicer looking products that is flexible, affordable, and easy to find. I've got some pieces I've made with rub-n-buff where I just reapply it every time I wear the thing, sorta like shoe-polish.