I tried it, and it worked great. Used basic 3-in-1 oil. I cut off a circular strip from the top of a white tube sock, and wrapped it around a wooden shim. A couple drops of oil on the tip, run it along the tops of the tracks. Do your painting, and immediately clean the rail with a fresh cloth wet with a few drops of isopropyl alcohol. Wrapped around a shim, this will clean the top of the rails in a few swipes.
It helps to work in small sections. The longer you let the paint dry on the rail, the tougher it is to get off.
Jim