Have you tried eraser pads? With some distilled water..onerous goes and easy peasy arrives with a cheeriness...I have a relatively modest Disco Antistat cleaning System. Does a good job, if a little onerous.
A soft brush under tap can help too...Years ago bought the Clapton 6 record set at a car boot for 50p - looked like someone had pulled a house down around them there was so much debris on them - just washed them in the sink with slightly soapy water - 10 of the 12 sides turned out fine
Aren’t they abrasive?Have you tried eraser pads? With some distilled water..onerous goes and easy peasy arrives with a cheeriness...