I have some radial discs that are copycats of the 3M ones (couldn't afford the real ones at the time), but they're rather stiff and plasticy and hard to use with rings. I've used the real ones at my classes last year but I don't remember if they're very different. Maybe the real ones would be more flexible.
I'm new here, but I've seen some of the things people are going through on here right now and I'm so sorry to hear about it too...
I can't use any of the store bought disc thingies. I've tried. Too limiting.
I use a bolt, nut washer, leather disc backing, and some layers of emery paper approximately cut into circles. A vast number of controllable variables. A learning curve knowing what you want, but I couldn't work with store bought.
CG that's probably a good reason why I have bought every abrasive and polish doo hickey made and you use 1or 2 things! No one thing is ever exactly what I want for a ring, pendant or cuff. I still almost always resort to sanding sticks for anything flat, curves are another story. I do like having lots of options though.
CG I'm glad you piped up. I was feeling very stupid stacking up those emery discs and my leftover chamois. They will eventually conform to get into areas I'd never get to with regular discs. I use those abrasive pens that I got Kit to stock up for me to remove scratches as well.
I can promise that I don't feel stupid using my homemade stuff. It's definitely not to save money, I just like that I can customize them a lot for specific jobs. I almost never hand sand, I'm too lazy.