Having never prepped any wheel bores this small, I looked around for something equally small to polish those bores. The Tamiya swab stocks/sticks measure at .058", but they could be sanded down to something slightly larger than the wheel bore to help polish the bore following similar techniques of the larger bore BSA wheels.
I'm not familiar with the dental items you mentioned. I don't know if they would be detrimental to the polishing process or not. Maybe if you provide some links to these mentioned items it would better help in determining the value. There was some information out there that mentioned using a nylon stocking to polish bores. Of course, common sense when using the nylon stocking only makes sense. You obviously don't want to pull the "full" stocking through the bore.

I'm just thinking out loud here... Anyone else, join in if you have any other ideas.