There are numerous ways to clean off the bits, including the screwdriver option. If I didn't have this otherwise-useless Norton plate, I'd simply find an inconspicuous area of sidewalk and do figure-eights on it with the DMT for a couple of minutes. It doesn't take much. Some plates don't even need any of this treatment, but both of my big ones and one of my little ones had rough spots on the outer edges and one or two persistent little devils right in the center.

And the $200 dia-flat plate is massive overkill. The $47 D8C is sufficient for all but the most fanatical hone lapper. The coarser D8X is good for harder hones, but it'll eat a Naniwa in no time.