I have owned the Sony XA7ES where the lens is fixed to the tray and hence it's accessible when the tray slides out. Whenever the player starts to exhibit serious skipping problems on certain CD's, I've used a dry cotton bud to clean the lens. This method works for me. I believe the dust and/or dirt from CD's have got onto the lens after many years of play that caused the skipping. I'm not as patient as Elizabeth in cleaning every single CD's everytime they go into the player.
You did not mention if you have experienced any problems with your player. If not, as others have mentioned, don't bother to do anything to the player.