Justin,
I recently draw filed a Rice barrel from Chambers. It didn't need much, but it certainly did need some (more than a few strokes). Run your fingernail across one of the flats. On my barrel, I could feel the milling marks with my fingernail.
If you intend to brown it, don't get super smooth and shiny. The browning agent won't work well on a finely polished surface. The browning will also cover up some of the scratches etc.
After draw filing, I went to about 220 grit sandpaper. Some guys can draw file better than me and don't need sandpaper afterwards.
I also rub children's sidewalk chalk on my file. It acts as a release agent for the small metal filings you generate. If they get stuck in the file teeth, they will drag a deep scratch in the metal. Card your file (Brush it with a non-metal brush) often and re-apply chalk.
Cheers,
Norm