Any tips for polishing the inside edges on a horn carve ?

[Sudsy]

Working on my first horn
I'm about to go at it with chopsticks and stuff wrapped in sandpaper, but if anyone has a better suggestion I'm all ears

 

[CuNosecap]

Needle files, chain saw files. sand paper. scotch brite pads of varying grits

 

[Sudsy]

Needle files, chain saw files. sand paper. scotch brite pads of varying grits

Yup, went that way, finished it this morning. What a PIA !
Came out pretty OK though, next one will be better

 

[Sudsy]

Next move is something decorative around the top and inlet my initials in brass into the flat top cap (what's the word for that part?)