When it comes to cleaning a Dutch oven with clay, there are a couple different methods that you can use. The first method is pretty simple and only requires that you have some hot water and a sponge. Just fill up your sink with hot water and add a little bit of dish soap to the water. Submerge your Dutch oven in the soapy water and let it soak for about 15 minutes. After it has soaked, take your sponge and scrub away any dirt or debris that may be on the surface of the pot. Rinse the pot off with clean water and dry it thoroughly with a clean towel.
If your Dutch oven is particularly dirty, you may need to resort to using some elbow grease (and maybe even a little baking soda) to get it clean. Start by mixing together equal parts hot water and white vinegar in a bowl. Next, sprinkle some baking soda onto any areas of the pot that seem especially dirty or stained. Use a scrub brush or sponge to scrub these areas until they are clean. Once you've given the whole pot a good scrubbing, rinse it off with clean water and dry it completely before using it again.