IME the best way to lap those stones is with the pencil grid under lightly running water in the kitchen sink. If the swarf is allowed to build it may defeat the purpose. For the 220 I would go to 120 grit sandpaper on a flat surface. Lapping a 220 grit stone with a 325 grit plate may not be advisable for the longevity of the plate.

Also , just IMO, no need for the 220 on razors unless you have a serious frown or chip to remove and now that you've got the 325 plate use that instead of the 220 stone. Set your bevels on the 1k Norton.