Peg, I use a clean white eraser sometimes, but what works even better is the eraser end of a Frixion pen. It seems to grab those little bits the best. Sometimes they even stick to the eraser and you have to clear them off to continue. I showed someone at retreat this trick and her comment was, "Where were you when I started this? LOL" Works like a charm.
By the way, I like your block. I haven't even started and probably won't for awhile. I still have the first one to finish FMQing on, but am happy so far.