Emery boards and cardboard
I use one of the dual grit kinds found in the beauty supply section of just about any store. I use the finest grade possible, the other side usually has a slightly rougher grit (if I can feel the grit, it's too coarse for me). Even if you use a coarse bright boy, the fine grit will eventually smooth out the scratches to a mirror like finish (but quite not as shiny as the gleaming process, but much quicker). It can be cut down if needed and I only use it for track cleaning; even after it's 'worn out', it still does a great job (mine is probably 5 years old). When it gets dirty (after a minute or so), I wipe it off on my jeans and that knocks off most of the black dust.
If I do add any liquid, it's either alcohol (70% or 91%, whatever I have on hand) or a contact cleaner (which makes sense to me as wheels on rails is an electrical contact). I don't know what exactly is in the various contact cleaners available, but since it's made for electric contact, it makes sense to use it (Goo Gone and other products, while they may work, are not formulated specifically for electrical contacts). I don't use a rag or paper towel to apply liquids, I find they snag, and wear down and leave lint...instead, I use regular, un-printed, pieces of cardboard. It is just rough enough to provide a scrubbing action and flat enough to not snag on points, ballast, etc. I spray or drip a tiny bit onto a (roughly) 1" x 2" piece of cardboard and wipe it over the rails after the emery board treatment to pick up any 'dust' leftover from the emery board treatment. When the cardboard shows the typical black streaks, I toss it out (or flip it over) and repeat. It's just like a Masonite pad, but I also get rid of some cardboard this way.
To check if your cleaner of choice leaves a residue, put a drop on a piece of glass and let it sit overnight (or longer) and check; the carrier will evaporate and leave whatever behind. While this much will not be left on your track, it will still show what might build up, and if it's sticky, greasy, whatever.
I don't spend any money on special products (like rail zip, or no ox), I've heard rail zip is synthetic auto trans fluid, but (even though it may work for others) I find no need for it (I have a small 2' x 12' switching layout that is easy to clean if it ever needs it. I've learned dirt/dust will stick to a film of oil or just about any residue (after the glass test, sprinkle a bit of dust on it and see if it sticks to the place where you put the drop of cleaner); keeping the dust down will greatly reduce the need to clean the rails; a finished ceiling will help a lot and I believe carpet traps a lot of dust (even creates it by microscopic tiny fibers breaking off during normal use/vacuuming (again, leave a piece of glass on the layout somewhere and see what kind of dust falls on it over time (btw, use glass for testing, not clear plastic, as plastic may have a static charge and attract/repel dust particles and give an erroneous result). Excessive vacuuming might stir up more dust than it sucks up, buy and use a high quality clean bag to filter out as many microscopic particles as possible.
I'm not passionate about my method for cleaning track (by all means keep doing whatever works for you) but I just wanted to share what I do, since no one else mentioned some of my methods.