I’ve been experimenting with short-fibre cloths, the kind that are wicking and soft. I used one dampened with distilled water to give each record a thorough, vigorous, and careful clean. A second cloth was used dry to buff each disc dry. I put each disc into a rack to airdry before putting into a new HDFE inner sleeve.
I am delighted by the results. The treated records look very clean and the noise is only surface wear on old discs.
After trying various alcohol/detergent/water mixes, vacuuming, and ulstrasonic cleaning, I think I have found the easiest and cheapest cleaning method, with no chemicals and no noise. I’m quite surprised that such an easy method can be so effective.