No matter how mint they look there will be crap there to get rid of trust me, ironx is ph neutral so safe on everything basically.
Give them a good wash with a neutral shampoo if they are just a bit dusty, then ironx,rinse clay rinse and dry off, get some finishing polish or fixer if you've got that and polish by hand, don't have to press hard or anything like that its just to cleanse the surface to get rid of any remaining nastys that could be lerking

yes then a thorough wipe down with eraser, apply the cquk thinnly and do a wheel at a time, apply, allow to dwell for a minute or two then wipe of with clean microfibre then onto the next one etc etc.
After an hour apply reload.