I've cleaned up a lot of old conventional track, some of it quite rusty, with a wire wheel in a bench grinder. I find this easier than sanding. You only need to shine the tops of the rails and the pins. Then clean out the rail ends with a drill bit. Might need to pull all the pins to clean them up depending on condition. Drive them in slightly before trying to pull the pins. When assembling track, make sure all the pin connections are tight. I crimp the web of the rail under the pin hole with dull wire cutters.
Track which is only lightly oxided (not shiny) can be effectively cleaned with a Scotchbrite pad.
I'm using a lot of salvaged track which performs well if you make the effort.
Or buy new track as suggested if you prefer.