How to economically clean old records

Try this method. It works remarkably well on dirty, grimey records. If, however, the record is scratched, nothing will help.

The age of the LP's is not a problem. I have hundreds that old or older that are in fine shape.

Your description of their care and condition is not encouraging however. As Calbrs03 said, scratches are non-reversible.

So are other types of less visible damage. LP's played on inexpensive or poorly set up rigs tend to be damaged by the mere act of playing, even if carefully handled. None of the LP's I had as a teenager is listenable now, even though I handled them more carefully than most of my friends. My "kid's" rig was destroying them, though it took better rigs and systems to reveal it. By then it was too late.

Clean a few that interest you and play them to see how it goes before spending alot of time, effort or money on cleaning the whole lot.

For me, the other half of the equation is a bundle of deep pile microfiber polishing cloths. I got a bundle of 25 16"x16" deep nap microfiber cloths (9,000 naps per sq. in.) from Sam's Club for $10. Add a handheld steamer from Walgreens for $30 and you're there (though I also use spray-on record cleaning fluid from a local used record store as well).

Put a microfiber cloth on the kitchen counter; put the record on top of it; spray on some record cleaner, run the steamer over it, use one cloth to wet-wipe and deep scrub it (the microfibers get deep into the groove); steam again to blast away the residue, and then use a third, dry clean microfiber cloth to wipe it off and dry it. Flip it over and repeat. Then put it in a dish rack to air dry.