An ultrasonic clearer might help. They are not cheap, but they do a good job.
Dave Burton - the Record Genie will clean them. He has two different ultrasonic machines. He has experience with moldy records and uses a Spin Clean on those, I think. I think he charges $3 a piece to do them with one machine or $5 to do them on both machines. He also has quantity discounts, 25% for 100+. Don't quote me on price, but he posted those prices not long ago. You could try some and see how that goes.
His business is Record Genie and he is outside Boston, but he has business around the country. You can find him on Facebook or at his website.
Record Genie
Dave Burton - the Record Genie will clean them. He has two different ultrasonic machines. He has experience with moldy records and uses a Spin Clean on those, I think. I think he charges $3 a piece to do them with one machine or $5 to do them on both machines. He also has quantity discounts, 25% for 100+. Don't quote me on price, but he posted those prices not long ago. You could try some and see how that goes.
His business is Record Genie and he is outside Boston, but he has business around the country. You can find him on Facebook or at his website.
Record Genie