I've seen pictures of the barrel polishing process that have sanding/polishing backers present. They are rubber, semi-circle profile lengthwise, and have a handle on top. Not finding any for myself yet, I've been various sizes of automotive heater hoses, split lengthwise, and cut to lengths desired. They work, and they're also harder to hold on to which aggravates arthritis.

Anyone have a source for what I've described?