There’s a gent named Jacques Pallas in France who sells artisanal washboards out of his workshop in the town of Poitiers. His company is called “L’inoxydable” (which means, I take it, “stainless steel”) and there can be no doubt but that he makes some very nice boards indeed. They come plain or fully-equipped, and he makes boards that can be played vertically (“à l’américaine”) or horizontally (“à la française”). If I had the cash, I’d buy one right now—probably the “simple inox.” It’s an elegant design with an interesting curved crimp and a nicely decorated steel headboard:

All his washboards come with snares attached to the front. I don’t know how that would work.

Unless I miss my guess, you’re seeing an L’inoxydable washboard in action here.

Take a moment to peruse Pallas’s catalog.