Something that not everyone is aware of is the multilevel error handling technology in a CD player. Therefore, a dirty CD may not produce instantly obvious audio problems but can nonetheless result in less than optimal audio performance.

Very severe errors - long bursts - will result in audible degradation including noise and/or muting of the sound. Even this may not always be detectable depending on musical context.

Shorter runs of errors will result in the player interpolating between what it thinks are good samples. This isn't perfect but will probably not be detected upon casual listening.

Errors within the correcting capability of the CIRC code will result in perfect reconstruction.

Not all players implement all possible error handling strategies.
Therefore, it is quite possible for CD cleaning to result in better sound. However, a CD that is obviously clean will not benefit and excessive cleaning or improper cleaning will introduce fine (or not so fine) scratches which can eventually cause problems.