WD 40 to remove scratches on vinyl !

Take 57 minutes out of your life and watch the Live Origin lecture on cleaning records. It does a good job to debunk all all of those sake oil salesmen on youtube.

WD 40 doesn't fix scratches.
BUT as the cleaner of last resort!!
If you have a non-scratched record suffering with surface noise which
no amount of cleaning fixes, then....
Wipe the record with a clean paper cloth wetted with WD 40.
Then rinse the record under a tap, trying not to get the label wet.
Voila! I have a small number of charity shop records which are
now quiet and play well. WD 40 saved them from the rubbish tip.

The dirtiest record in the world can be cleaned sufficiently without WD-40. 

Spray WD-40 on brass and see what happens after a week or two. WD-40 is corrosive to some metal; which might not be good for yout cartridge.

I have found the best product for cleaning is called "Last"
Do not know if it is still made.
I simply use a little warm water on a lint free Clothe.