I've picked up a bunch of old Bachmann EZ and Life-Like Power Lock track from various sources recently and they were in varying conditions from new in box to horribly oxidized. All they ever need is a good scrub with one of these blocks and they're clean, shiny, and work like new. I don't even bother running track until i've given it a once-over with my PECO cleaner. I don't have a dedicated track cleaning car so this little $7 block is worth its weight in gold to me. When the block gets loaded up with oxidation or gunk I simply run if over the leg of my blue jeans and it comes clean. That little modeling trick also works with sanding sticks and small brushes. Just be sure you're cleaning off stuff that'll come out in the wash. I suppose you could use a real tight fiber lint free towel as well. But denim is excellent. So before you throw out that old pair of blue jeans cut yourself up some rags out of it to unload your cleaning blocks, sanding sticks, files, etc.

The Abrasive rubber block rail cleaner works well in very localized track cleaning. I use the block to clean area that need an extra cleaning due to a build up of grim.

I like this better than the similar product by Bachmann, and the price is better! It also come in a little clear plastic box which - for me - makes it easier to find and store.