The O-gauge track you started with looks a lot better than most of the track I have!
Burnishing is, according to Wikipedia, “the plastic deformation of a surface due to sliding contact with another object. Visually, burnishing smears the texture of a rough surface and makes it shinier…Burnishing is not always bad. If it occurs in a controlled manner, it can have desirable effects…[Burnishing] prevents corrosion and stress corrosion…[and] closes porosity…”
But: “The wire brush is primarily an abrasive implement…”. It has been reported on the forum that American Flyer track is not plated and therefore may be cleaned by abrasion without making it more likely to corrode. While I doubt that this is true, I know that Lionel and other three-rail track is plated, probably with tin, which can be removed.
After researching it, I believe this is a good tool for burnishing railheads, especially those already in place on the layout:
http://drillsandcutters.com/8-hss-jobber-length-drill-bit-blank/?gclid=COXrk6vV28ECFZNbfgodXkEAbw
Note that carbide gives a rougher finish, this is less brittle and smoother.
I’m picking one up, only $2.07
With Aloha, Will
I use tubular track, and clean it by running the train. The train makes a very narrow polished strip on the very top of the rail. I find that running the train is a lot more fun than polishing track on a wheel. Just MHO.