Hi! I wanted to let anyone doing a build know about this sand"paper" I bought at Lowe's. It is made from what looks like silicone, (you can wad it up and it springs back to shape). The cool thing is that you can bend it around anything, (its super-thin), and it seems to last forever! I used one small 4x6 sheet, and finished my entire Doopydoos E-11, my grappling hook, as well as another small project, and it still looks like new. I think it will be perfect for getting in the small teeth holes, (it doesn't tear), as well as the eye openings, etc. of my armor build I start tomorrow.
I bought the 220 fine grit, but they may make different types. It is called Sandblaster Pro from 3M, and costs about 4 bucks for a 4 pack. Hope this helps someone!