Hey Kevin, if your ever worried about metal on aluminum when doing something similar you can also use a used old 1/4 flag pole. Just cut it to your desired length and use a knife to make a slit for the emery cloth and put a couple wraps of electrical tape around the fiber glass to keep it from splitting further. I use this method a lot when polishing hard to reach places.. I used the same set-up as you until I wore through emery once or twice and decided to I needed find a softer shaft material.
