Y'all can make your own too. Just need to drill hole in thin plywood. These ones I've made are not perfect, but they certainly work. What you do is, you put tape around the edge and the hole. Duct tape or electric tape. Put just enough on to make the jar hold tight, and then you can screw the lid on and off while in the holder. Never have to touch the bottom of the jar, just the lid. Like I said, it works great.
The tape keeps the jar tight in the holder so you can unscrew lid with one hand.