I have noticed it does almost no good to clean the wheels and not the track, too. I use Simple Green to clean track and wheels. I have never had anything but great results.
To clean wheels, I do two steps:
1) turn the loco over and clean all wheels that are unpowered (that I can turn by hand) and the center pickups by using a cloth pad dremel soaked with a bit of simple green. I have noticed that getting the rollers clean and shiny is a key to good running.
2) I then set the loco (and tender) wheels on "O-gauge rollers" at about 10 volts while the loco is standing in place (FIRST PHOTO). I got mine from Micro Mark. The photo shows a Lionel Atlantic set up, along with one roller in front so you can see what it looks like loose, and the package in back.
Anyway, the loco sits on these and spins its drivers: I hold a Q-tip or brush with simple green against it and clean it. In a few cases I have had to hold a blade against it to "machine" accumulated crude off from an old used loco I had bought.
To clean track - I had a Lionel Christmas track cleaning car but it did not do a heavy enough job. Once a week I clean any particular bad sections by hand. I then run my vacuum car (top in PHOTO TWO) about three times around each loop, then the heavy duty track (blue) cleaning car about ten times, and then I run the track eraser car (red) for about fifteen minutes, just attaching it to a normal train.
The vacuum cleaner car's guts are from a Dustbuster. Originally I powered it with a recitifer from track voltage, but the vacuum sucks best at 20 volts but picks up best if pulled at slow speeds around 11 volts, so I now power it with a 18V B&D rechargable battery mounted on the flatcar towed behind.
On the lower level, the track cleaning car to the right works well, just a weighted lever from the back of a flatcar, on which I clamp a cloth pad (old denim works best) wrapped about six times around a wooden block and soaked with simple green or alcohol - tow it behind a loco for a while and the track cleans up nicely. The red car on the lower left is a boxcar with a track cleaning eraser that a weighted beam lever holds down against the track with about 4 ounces force. Sometimes I just run it with a freight train continuously. Most visitors never notice.