Disks exposed to the weather like that and attempted to be cleaned should be considered single use if you were trying to recover the files. Since you don't care about the files I would not use those disks in any drive. It's not worth the hassle and potential damage.

If you want to make floppies, then you probably want to find the machine(s) used to make them. They are probably still around somewhere, but good luck. Making a floppy is a known science, but you'll probably want a machine to get good results, and not sure if it would be easy to create something yourself.

Oh well, can this be done, at all? 🙁

I'm just a layman, of course, but my first thought was cleaning them with purified water.
An ultrasonic washing device might get dust/remaining particless off, too, maybe?

Anyone else having ideas, please? 🥺

from my experience with cheap floppy disk after soaking in the rain,
when the water is inside the disk, it will break the magnetic layer and the disk is no longer readable.

I assume you're doing this for fun, as floppy disks are still possible to find in local selling groups.
You can remove the metal door and the spring, then carefully slide a knife near each of the upper two corners and twist it gently until the two shell halves separate with a crack sound. There are plastic posts that will break, but can be easily glued back again once you're done cleaning the disk.

With the shell open, you can wash the both the shell and the media. Tap the media gently with a tissue to dry it, and ensure the shell's inner cleaning layer is also dry before putting everything back together.

Jo22 wrote on 2024-11-21, 14:55:

Oh well, can this be done, at all? 🙁

The only people I hear do it are data recovery people. Very few spend the time and have done data recovery successfully. And expect that the disk is essentially "destroyed" after it is attempted and need to clean your drive heads after it.