Quoted from NickBuffaloPinball:So, my approach, I wipe it down with a dry microfiber towel once a month or so. I think waxing twice a year is more than enough and using novus 2 once or twice a year is more than enough.
While I have very little experience in the matter I have have read a whole bunch on here and RGP and to me it makes sense that you can overdo it and actually do harm to the machine.....with my LOTR NIB I've used the microfiber towel a few times and don't need to wax it yet....
With older machines that don't have the diamond plate or extra coatings, maybe more TLC is required....