OK - it's got some age on it (10 years?) but it's recently becoming more and more temperamental in that it will play some DVDs and not others. No rhyme or reason can be detected. When it's refusing to play, it says "reading disc", followed by "insert disc", so failing to recognize there's already one in the machine.
I think we need a new DVD player but my husband is concerned that if there's a more fundamental problem, getting anew DVD player won't solve the problem.
When we used to play audio tapes on a tape player, you could get a "cleaning tape" that cleaned the bits that actually touched the tape to play it and got dirty. Maybe a thingy (technical term) inside the DVD player is dirty. Can you get something that would clean it?
I have a feeling that sloshing about inside with soap and water might not be a good idea!