For a whole badger you are going to need to work quickly. Dry, hollow out and varnish a small stump. Put about a gallon of marine epoxy in the bottom of the hole. Press the badger in head first. Once the epoxy has dried, you'll be ready to lather up. Make sure your buddy stays around. It might not be hard to lift your new brush but it's going to take some doing to swirl that bad boy around on the puck of soap.
I was thinking you just put a stick in one end. The drip stand would be pretty big though.