CD Treatment

I occasionally use Shinola. It makes no claims other than being an effective cleaner.
I believe it is now a Mofi product.

The problem with CDs (and Vinyl for that matter) is balance. Depending on the CD reader, a CD can be rotating at 500rpm. If the CD is not on perfect balance, the vibration not only effects the hardware holding it, but the quality of the data read ie bits can be and are usually misread, requiring high speed corrections on the fly. Only high quality CD readers (and thereby supporting electronics) are successful in this and the reason that they DO sound better.
Vinyl is much the same in that the centre hole is not actually IN the centre of the LP. Having a rare Nakamichi Dragon CT, I can see it correcting the centre with 99.9% of my old and very latest albums.

I have used Walker Audio Ultra Vivid CD cleaner and it works well.  The soundstage is more open, deeper, vivid, and harmonics are more realistic. I assume that it polishes the CD so that the laser can more easily read the CD and there is less jitter.  It seems to last as long as you keep your pinkies off the disc.

I also used a device that demagnetized CDs as was first noted by Arnie Nudell.  It had some of the same sound improvement characteristics as the Walker Product. Unfortunately it had to be done every time I played the CD and the damag process took about two minutes. 

Had anyone tried spit...and then wipe it off with your shirt's sleeve?

Kozka, thanks for the morning chuckle.