I ordered a Realistic Magnetic Bulk Tape Eraser 44-210 today - it even has a floppy disk on the packaging and it is an RS brand, so what could go wrong? I will report whether it convinces the recalcitrant C-64 disks to become PC friendly. At $33 including shipping, I had to think it through in terms of how much use it could get, but what the heck - I figure I can use it to crack walnuts if nothing else..
It came in. Opening the package, without undue force, a piece of the handle (around the switch, of course), was cracked and fell off. More than likely, this was do to shipping issues and it should have been packed better. It is heavy and dropping the package in some way could have caused this. I glued it back. This is actually the first time that I can remember getting something off of the bay that was damaged. I am not interested in pursuing the matter with the seller.
It erases floppy disks, no question about that. I tested it out on several. So, it works. You can hear it work. The duty cycle in the instructions was followed. You can feel it when it gets hot.
It did NOT, however, fix the C64 disks that I had mentioned. Testing two that I had already worked with and cleaned, it did have some effect. That is, I could start the formatting process on the PC (which I could not do early), but they could not finish without numerous retries and too many bad spots.
Some times in life, you just have to say "these disks are toast".
It is not a total waste as I will get further use and test some more C-64 disks at some point and I will, on occasion, erase media with it....and crack walnuts.
That's all I got.