I also have a CMX car, using denatured alcohol as the solvent. It’s pricey but works very well in combination with my “gleamed” track and metal wheelsets. It takes two small locos (e.g., Athearn GP9) or a high traction one (e.g., traction wheeled Challenger) to get it over the turnouts.
I’ve considered building a car with the Masonite pad beneath for more routine quick cleaning but have not got around to it yet. Maybe I can find an old post on that. Edit: the following thread includes info on the “John Allen track cleaning car” and other info on track cleaning.