I’ve used tooth picks, the end of various sized chop sticks and cue
tip ends depending on the diameter of the hole. The cotton on the
cue tip holds the buffing compound very well but you must peel off
some of the cotton and its a throw away after almost every use.
Bernardine Fine Art Jewelry
bamboo skewers work well just chuck them up in a dremel or fordom
Hoyle Lapidary Arts
Iron Wood (Lignum Vitae) slivers shaped round will do a fine job -
and the take easily to diamond polishing grit bort.