Need to hone or sand inside a small tube? 

Try this.
Open a cotter pin and insert the end of a 6 to 8 in. piece of emery cloth (you're choice of grit), close the cotter pin and wrap the cloth around the shaft of the cotter pin. Now, insert the cotter pin into the chuck of you're drill like using a drill bit. Be sure the cloth is wrapped properly so the grit is exposed. You now have a miniature honer for many different jobs. When the cloth wears, just tear off the worn section to expose a fresh piece.