Do CD treatments improve rips?

I rip using MAX (Mac) with CDParanoia option "don't allow to skip" selected. Computer reads music disk as data disk with proper check-sums (zero errors).

Treating a CD is only beneficial (and that's questionable) for when the CD is being read in real time by the CD player. Ripping is more a function of the software. Most software has error correction so it will reread the CD until it gets it right. In fact a more expensive CD drive will not give you better rips than the plain old CD drive that came with your computer, but it may rip faster.

A few years ago I tried a few rips before and after treatment. I timed the rips. In some cases (not all) the treated rips were faster, but both ways checksummed the same. So it's basically a waste of the extra time (spent treating the CD) and the money for the treatment to gain 30 seconds in rip time. Just use some water and clean the damn CD's.
Also, it has been proven that iTunes on Macs (error correction has to be activated) rips bit-perfect.
And if two rips checksum the same and you hear a difference, well.........

Hoff48 - I'm not sure that Itunes rips bit perfect. My Itunes rips on Mac, with error correction activated, CDs that are not readable by MAX set to "not allow to skip option". Error correction on music CDs is pretty loose and the only way to read it bit-perfect is to read it as a data - as MAX does and Itunes doesn't.

I use dbPoweramp which consults a database containing the CRCs that others have reported for each track. Of 1500 CDs, only a handful weren't in the database.

I found no benefit to cleaning the CD unless it ripped with a CRC different from everyone else's. In those cases, I cleaned the surface of the CD and for the rare, tough caes also used Auric Illuminator.

Although the CD drive may retry before software retries, the read may ultimately fail. In many such cases, after a quick cleaning, CDs then ripped cleanly on a single pass.

My guess is that most of the treatments we used over the years simply cured the kind of read errors I experienced; since the ripping process is not real-time, the errors could be detected and corrected. When a CD is playing in real time and there is a read error, the player either has to go silent or has to fake it.

So, the treatments most likely did improve sound quality on real-time playback (on CDs that had read errors).

Once you rip a track to a bitstring whose CRC matches that of 20 or 30 other rippers (strong evidence that you have read it without error), you cannot rip it any 'better.'

That is, there is one right answer (one correct bitstring and one correct CRC). If you get that answer, then cleaning or treating are pointless.