I would highly recommend sending your records to PerfectVinylForever, a record cleaning service. His is no ordinary ultrasonic cleaning process; it’s a multi-step cleaning done with proprietary equipment that he designed himself. I know, you’re thinking “snake oil” — I thought the same thing. I had always used my VPI record cleaner and thought it couldn’t be beat. How wrong I was — PVF is amazing. Records sound completely black with improved sonics. Even some of the pops and cracks are gone. I’ve now sent nearly 50% of my collection to him and will eventually finish the remaining albums. It’s absolutely amazing — even my old “college frisbee albums” sound good after a PVF cleaning. I’ve included his website link or you can just search for PerfectVinylForever.