A couple of the Sourdough Bread Resources that I found mentioned using rice flour at the final stage of bread making when you are putting the dough into a batard. I can vouge for this. At first, I didn't have rice flour so I was just using plain wheat flour. I would get a flour crust on the batard that got worse over time. And I was never really able to clean it.
One day it dawned on me that I didn't need to buy rice flour. I have white rice and I have a flour mill attachment for my KitchenAid mixer. I realized I could easily make my own rice flour. From that point on, I started using rice flour, and it works so much better. The rice flour does not absorb water like wheat flour so the dough doesn't stick to the batard and it releases so much easier into the baking dish.
When I started using the round batard, I made sure to only use rice flour. You can see from the picture how much cleaner the round batard has stayed compared to the oval batard even though it has been used more often. The dough always just plops right out into the Dutch oven leaving no dough residue in the batard.
I now see the importance of using rice flour in bread making. The KitchenAid flour mill is a bit of a luxury but definitely nice to have. I wonder if it is possible to create rice flour using a coffee grinder or even a rolling pin with the rice grains in a Ziploc bag. It only takes a teaspoon or less to coat the batard before plopping in the dough. If you can't make rice flour at home, it is definitely worth buying some to have on hand for your next break making session.