What's the best way to clean the dust from mounts. If I just use a cloth to wipe them off, won't that just push the dust down into the hair? What about a vacuum cleaner?

Vacum cleaner, compressed air or a static cloth would be good.

I spray mine down with an anti mite spray that is safe for use in the house, and every nown then I'll se a beeswax funriture polis on the horns to keep them dark lustrus and prevent cracking.