Today I had nothing to do so I decided to try and make a track cleaner car. I cut a piece of masonite about one & a half inches long. I then glued two roofing nails to it. I found an old caboose and drilled matching nail holes in the bottom and mated the caboose and the cleaner slab together. I had to add weight to the cleaner block as it was not pressing hard enough on the track. Not sure if I will add some type of cloth to the slab to put cleaner liquid on it. I don't have a layout to test the cleaner on but it was a satisfying project. I also weighted down the caboose for stability.
Cool project! I like that kind of creative project, making something using whatever's around, my brains and my hands. Keeps the mind sharp and the fingers nimble.
I believe the method you describe and the results you show have been established and widely used for many years. However, it's one thing to nod as you read a description of a process, understanding and following along as most of us do, and then actually producing one's own working copy of it. So, well done, count yourself among the intrepid modelers of old who had to use their brains, develop skills, scrounge some parts and materials, and cobble a workable item out of it all.