what is the best WAY to clean a DISC???

You have to tell us a little more of what you are trying to accomplish.

If you follow tradition, the term disc refers to optical media, disk refers to magnetic media.

I assume you are wanting to clean optical media (CDs/DVDs). I wash (fingers or microfiber cloth only) with a 50/50 water/isopropyl (rubbing) alcohol solution - to remove grease (fingerprints). I then rinse in plain water and dry with a microfiber cloth. More expensive would be to dry with lens paper. If you rinse with distilled water you could probably air dry without getting water spots (the reason for drying)

Monk

I use the same thing to clean my computer keyboards, monitors, laptops and discs...it's a 50/50 mix of 70-80% isopropyl alcohol with distilled water and a microfiber cloth.

As said, use a mixture of 50/50 Isopropyl Alcohol & Deionised Water (dont use hand sanitizer - it contains IPA but also mosturisers which cause surface to grease up ang give read errors - i get my IPA from eBay - 100% pure n just dilute it with 50% deionised water). Deionised water can be bought from most stores (Tesco, Asda, Sainsbury's etc as its used for putting in irons & car batteries) - dont use tap water as it contains minute traces of minerals which over time can scratch the surface

Lastly, dont rub in a circular motion, as this can cause read errors and make the disc unreadable. Start from the centre hole and work your way out to the outside - repeat this all the way round.

Quite in depth, but this also applies to TFT screens - works a charm - just remember - 50% PURE Isopropyl Alcohol & 50% DEIONISED water

I am betting he means a Hard Drive :)

Steve