My layout is in a semi-finished basement, which it shares with a gas powered furnace and clothes dryer. In order to avoid carbon monoxide buildup, there has to be a certain amount of opening to the outdoors. (I worked for a natural gas utility for a while, and there's a formula for calculating this, which I forget.) Anyhow, even though the openings are screened, this means that there's a certain amount of unavoidable dust that's going to come in from outside, as well as dust that will fall from the ceiling, on top of ordinary corrosion of the rail.
So throughout the layout's history, I've experimented with track cleaning cars. One I've tried is the Atlas (video here). This hasn't attracted much enthusiasm on forums (if that's worth noting). I think one problem is that rotary abrasive disks don't actually seem to work very well as track cleaners. So I tried this one out and eventually set it aside -- a little sad, because it costs as much as a diesel. One thing I did was body mount the couplers, a big improvement.
The other day I decided to pull it out again. I had a defective DCC decoder on hand that would control the motor but not the lights. But this didn't have lights anyhow, so I mounted the otherwise useless decoder in the track cleaner's 8-pin factory DCC plug. This meant I could run it on high no matter what the loco that pulled it was doing. Looking at the Atlas video, I remembered it had a vacuum cleaner attachment. Although the rotary abrasive pads didn't work, I decided to try the vacuum cleaner again. Hmm, it works!
The version I got is lettered for the US Department of Transportation as a "Gage Restraint Measurement Vehicle", which was probably developed from the Mark VI Frammis.
I love it! But in the Atlas video, I noted the dust it picked up after just one trip around the demonstration layout. Here's my result after running over maybe 40 feet of my main line:
I now think this will have a permanent place in a track cleaning extra. Glad to get some use out of it after some years! It doesn't polish the railheads, but it picks up loose ballast, dust, bits of foam, and general debris.
The best track cleaner ever, at least that I've found, is the old Revell from the 1950s. I stripped mine and lettered it for the Santa Fe: