Gator Grip Universal Socket
The problem? The instructions recommend that you use a 'mixer' - which is this metal thing that attaches to your hand-held drill. Unfortunately, the mixer that Menards recommended requires a 1/2" chuck and my drill doesn't open up that wide. So, what's the solution? This thing above: the Gator Grip. It is perfect for this application - as it turns my simple drill into a socket that will hold the mixer stick.
It was $11.99 so hopefully I'll find more than just this one application. The packaging calls out using it on stripped/rusty/broken nuts and bolts, so it might be good to have on hand.