It's not quite so simple that it either gets read or it doesn't. Well I guess it kind of is, but the complication is that there are algorithms to make up for minor data-loss, where the player 'guesses' the missing bits and carries on without skipping. However the theory goes that the fewer guesses the software has to make because of read-errors, the more accurate the sound. So for that reason your discs should be as clean and scratch-free as possible.
That said, I can't see why such a miracle system would be any better than cheap denatured alcohol.
As for the sound...easy way to tell. Rip a song off a CD before cleaning it. Rip it again afterwards. Load them up into audio-editing software, invert the phase of one, merge it over the top of the other, and if you're left with utter silience then there really is no audible difference. You can't fool science.