Do the laser cleaning CDs do anything?

I had such a device from Discwasher once. NEver could discern any difference using it. I stopped using devices like this in that they appeared to do no real good and could potentially do harm if say residue was left in place that might affect the optics negatively. Lsers and optical circuits in most players are well hidden out of sight so no way to know via visual inspection often. Unlike cleaning records, where the record can be visually inspected for wear, residue, etc. and sonic effects if present are usually clearly evident.

The scenario that has come up that prompted me to use my Discwasher device was when a player was already having problems playing discs reliably, ie skipping, dropouts, etc. and cleaning the disc itself did not help. At some point, if a player is already apparently not working as it should, there is probably little harm in trying to clean the laser however possible. But again, I have not had much success with the Discwasher device delivering any results.

works almost the same way as if you hit 100mm nail with table spoon instead of hammer.

I used one of those on a Sony Playstation for my son and it worked. Before using it the disk would not play. After using it the disk worked. Never tried it on a CD player

Recently got an RCA/Discwasher cleaner for CD/DVD laser lens.
It is a dry system. No fluids involved. There are several
tiny brushes at various positions around the disc penetrating
and perpendicular to the shiny side of the CD). At a price of
$15 it seemed worthwhile + it has a "demagnitizing"
function! as well as 9 diagnostic tests!! AFTER USING IT THE
FIRST TIME IT WAS LIKE A COMPONENT UPGRADE!!! BETTER THAN
CHANGING OUT POWER CORDS!!!! Sorry, couldn't help myself. For
the few bucks it cost, why not just get one and see if you
hear something magical? I did not.