OK one more question on this.
I'm leaning towards trying the emery cloth around drill bits. Should I be aiming for drill bits bigger or smaller than my intended gauge of string?
For example, a #30 drill bit is .1285 in diameter and I'm using a .130 B. I'm not sure how thick the emery paper is, but if the paper around the bit exceeds .130 in diameter the slot could wind up too wide.
Also regarding the emery cloth, is there a preferred grit? Is higher grit better?
EDIT: Found the answer reagrding the bit size (should be slightly smaller to accommodate the thickness added by the cloth.) The big challenge will be finding fine emery cloth. Can't really tell if the big hardware stores around here have it or not.