These were the other things ordered with the cups. They are brush rinsing basins for the groom and his friends in the same profession. I don’t know the name for it in English, but they create forms for teeth as well as false teeth by mixing various concoctions. One of the processes they use involves a little tub of some sort of resin powder they apply with a wet brush. Both a reservoir of clean water as well as a rinsing space for the dirty brush is required so he requested a split basin with indentations for placing the brush when not in use.
I made them by coiling up a round wall, cutting it free at the base, reshaping into a split basin, and re-attaching to the base slab. It’s glazed with rice straw ash glaze and a dark clay slip is applied just to the lip under the white glaze. They were fired on a bed of rice straw ash to give the bottoms some interest.