I have tried it on some cheap/knackered records and yes it 'can' improve the sound somewhat (wont help with styrene burn) .. But it seems to leave a milky sort of colouring on the vinyl - visible on the deadwax under a strong light. You do have to wait until it has all gone clear before removing and yes be careful not to scratch the playing surface, you can put a small tab (cardboard) under the glue edge to help with removal. Having said all that I wouldn't do this on any records you value and other methods may achieve the same improvement...
