Shiny aluminum and shiny copper, I use a scotch brite pad going in only one direction like you do on glass. Anodized aluminum, I don't touch at all! Play it like it is. Media blasted copper and aluminum i touch up when needed with the scotch brite pad. If you condition anodized aluminum, you will end up removing the thin layer on anodizing and be left with normal shiny aluminum... Same scotch brite on slate. Primos conditioning stick on glass and crystal. With pot calls, the least amount of conditioning that you do, the better. That dust is material that you are removing. I have literally worn holes through slate from conditioning it over the years. Less is better.