I've put the brush in a bucket with some Jif, dunno if that will do anything. Seriously - do I need to wash the dustpan in the bathtub, or what?
(It's one of those ones with long handles for both, iyswim. If it makes a difference.)
Oh, and there might be some broken glass in there too.
(I probably should have asked MN earlier in the cleanup process, but there ya go ...)