Try to train them...again, or simply shoot them?

I would assume I am not the only one to have experienced this.  A friend, mate, relative or relatives friend damages a  lp or CD disk.

No matter how much I have tried, it is usually time not well spent.  I just got my CDs back from my son.  They were all fine and in "jewel" cases...some mofi.  Well they, son and girlfriend, decided to put them in a vinyl carrier.  The disks slide into a pocket and now most disks have scratches...which get worse taking them in and out of the "carrier"...and most have fingerprints/food on them.  

This is a high fidelity/stereo software concern I have had all my life.  Loaned some LPs to a friend, many "special" pressings...and yes, they came back damaged......don't you just love added ticks, pops and skips?

I have had a little success with the cd/sacd disks by giving them a bath...that will get rid of the food and fingerprints, but does nothing for the new groves across the playing surface.

Whomever said, "perfect sound forever" .....if they are not already dead, perhaps some kind of punishment, like listening to a David Lee Roth disk skip for a few years. 

Oh and, perhaps you have had luck, but trying to explain how to safely handle a LP or Disc is very much like trying to tell a politician how to be honest.