FatGripz makes a small grip that I use on all my used old dumbells. I found without harsh chemicals I couldn't get the knurl totally free of rust and it would just be annoying. Where as this option keeps me honest for biceps/delts, a little sprinkle of gripwork, really comfy for pressing movements. https://www.amazon.com/Fat-Gripz-Ones-1-75-Diameter/dp/B077H11LDG You can mount them on bands as well if you're limited at home. Much more of a versatile tool then the more visible blue FatGripz that are 2+inches thick.