How to add padding to a metal ring gag

I just picked up a spider ring gag similar to the one here: … c7575.html The issue is that it’s metal against my teeth, which I’m not entirely keen on for extended wear. My question is: what can I add to pad it so there’s a buffer between the metal and my teeth? I was considering electrical tape, but I’m unsure if the material or its adhesive might be toxic. I’m fairly new to DIY projects, so I’d appreciate any advice on how to protect my teeth without introducing anything harmful.