Verified answer

I'm hoping you mean dry dust....versus mud. Dry dust should come off with a vacuum cleaner

if it's mud let it dry first then use a vacuum. If that doesn't work then a soft bristle brush....like you could try an old CLEAN & DRY tooth brush. Good luck!

To keep them clean after you clean them I would spray them with a suede shoe spray since you seem to love them so much it should protect them better.

Try using a vacuum first. If you just start rubbing on them to try to get the dust off you might ruin them.