My SS PCS has become stained on the cast iron top and otherwise just kind of dirty. It seems like I remember an article or perhaps even on here where someone uses a random orbital sander to clean up the top and make it all shiny again. What grits of sand papers would you recommend? My thoughts are starting at 220 and going up to maybe an 800 or even 1200 then applying a CNN pastes wax and buffing it out. Feedback please,