So the toothbrush bristles never actually touch the grooves.I have a rather unconventional method for cleaning vinyl. I use my Phillips Sonicare (ultrasonic) toothbrush. In a bowl of tepid water with a couple of drops of washing up liquid, I submerge the record, put the tip of the toothbrush to the central hole and with a finger from the other hand, press so that the central hole and the top of the toothbrush make a good contact, switch on and on very dirty records you can see the dirt leave the surface, It doesn't take more than about 10 seconds and the dirt will have been removed, rinse and dry on kitchen paper. That's what I've done for many years and no labels have ever been damaged. I got the idea from when I worked as a jeweller and we used an ultrasonic bath to clean jewellery, you wouldn't believe the amount of filth that collects in jewellery, it always makes me gag when I see TV chefs preparing food whilst wearing rings or bracelets or watches.