Soft paint brush from the art store
I actually have an artist’s paint brush which says "Finest Russian Sable" and that sounds like the sort of thing that might appeal to an obsessive audiophile.
We could have threads with discussion of the effects upon SQ and Soundstage of various natural and synthetic bristles. I find that the Siberian Chinchilla is especially effective at image specificity, but regular old North Plains Mink comes through with that inner detail and insight I prize the most. I always dust with Beryllium powder for those evanescent transients too, making sure to breathe deep for full effect.
Actually I think the AC/DC suggestion was the best.