The part about head cleaning says "high purity" isopropyl alcohol and then says 70-99%. There's little reason to buy anything other than 99%. Additionally some of the same cleaning swabs and wipes sold for fiber optic patch cable and bulkhead connector cleaning are well suited for this.

These are low cost generic/bulk items you can buy from chinese sellers via Amazon or other sources. If it's good enough to clean 9/125 singlemode fiber it should be good enough for floppy drive heads. Ignore the reel-type cleaners that look like a mini betamax tape, and the push click cleaners, which can only be used on real fiber stuff. Go for the swabs and kimtech wipes.

visual examples of what the products look like:

https://focenter.com/products/fiber-optic-cleaning/productio...

https://www.occfiber.com/product/kimtech-lint-free-wipes/

Magnetic field cameras exist:

https://matesy.de/en/products/cmos-magview

https://en.wikipedia.org/wiki/File:Visualization_of_magnetic...