Since the wooden/metal tool as shown seems to be completely closed (or nearly so), I don't think it's for gripping anything round. It's more like a pair of pliers for squeezing two things together, round or otherwise. And the wood/metal tool does the squeezing while you push against them.
Sort of like an installation tool for snap-in cord grips.
Ah! It's for grabbing duplex receptacles while twisting them around so they're U-ground-UP! No, wait, wrong side of the Atlantic...
