Rattlesnake Beans Revisited

Rattlesnake beans are hybrids of pinto beans, but they come true when replanted, as I learned this summer. We ate most of last year's crop as green beans, but I let a few dry on the vines. The dried beans were delicious cooked with a little cumin.

I also saved some for seed. We planted them. They were successful. We didn't eat them as green beans, so they've all matured. The pile of dry pods in the photo is a tiny fraction of those still on the vines. Now what?

It would take hours to open the pods by hand. How did the Native Americans in the Southwest shell dried beans? Research is needed and suggestions are welcome.