Laboratory grade isopropyl alcohol (also known as isopropanol) is fine, so long as it is highly diluted in water. I cannot imagine using it undiluted directly on an LP surface. Furthermore, I wouldn’t use cotton; it’s fibrous and will leave tiny fragments on and in the LP surface, or at least that’s possible. A standard recipe is 25% isopropanol and a few drops of non-ionic detergent (Triton X100 or Tween20) to reduce the surface tension of the water. That’s what I use in my VPI HW17. There are HUGE threads on this subject. When it comes to ultrasonics, I am convinced it works, but I am not yet convinced about optimal ways to do it and so have not yet adopted the method. But for you (Invictus) to poo-poo the whole idea is rather silly, unless you were being funny. If the latter, you were successful.
Cleeds, It’s simple. Alcohol will remove that which is soluble in alcohol. Oily deposits from fingertips, etc, are not so soluble in water alone, but they are more easily removed with dilute alcohol. Can you imagine that there might be fingerprints on second-hand LPs? That’s not too difficult to imagine.
