I just did a little experiment. Also being a model railroader I use a lot of small tools. What I tried was impaling a good quality wine bottle cork on a COARSE SQUARE NEEDLE FILE. The coarse grade I tried was really coarse, It was one of those made with sintered-on grit. Not one with a conventional finely cut surface. I found these at my local "old time" hardware store for $.50 each. The grip in the cork seemed very good and no crumbs came out later indicating that the cork was merely pushed aside so it could spring back later. Of course the file would have to be broken-off to shorten it for the Dremel collet.