There are basically 2 kinds of solvents, as I recall from chemistry classes...
Polar and Non-Polar solvent. It has to do which kind of molecules of dirt the solvent has to dissolve...
Alcohol-based solvents clean up things that can be diluted with water, which includes some kinds of grease. It will not clean up some carbon-based residues that can only be cleaned with Non-polar (oil-based) solvents.
???
Just look at it this way:
Alcohol mixes with water, so it can mix with things that can be diluted also with water...
Oil does not mix with water, so it can mix with things that cannot be diluted with water, as carbon-based stuff...
When I do loco servicing, using oil-based solvents is mandatory if you want to clean out the carbon residues on rotors, sprockets and such, and alcohol is used to clean out the rest...
Since I always change the tires after cleaning loco wheels, I first give them a round with an oil-based solvent, and then a round with alcohol and finish off wiping them with a dry cloth or such... This gives excellent results...
When it comes to track, the same procedure could be applied as I see it, but that is of course a tedious way of doing it.
Lighter fluid (and also most commercial cleaning stuff like "Ajax", in your store) can do "both"... The great thing about lighter fluid is that it evaporates quickly and does not leave any residues on the track. A commercial cleaning agent usually needs a second round of plain water to remove the residues....
As mentioned earlier, rubber & alcohol does not go together so well, so when cleaning the tracks with alcohol you should have a felt pad car or something to wipe most of it off at the end of a "cleaning train" since alcohol evaporates rather slowly...
I am not certain about the effect on the C-track roadbed by alcohol, but since C-track "ages" and becomes more brittle for some reason - I do not exclude possible long-term deterioration issues of the C-track roadbed using alcohol...
But to cut it short - Yes, alcohol is a good track-cleaning solvent...
