What teapot does not need a brush?

Purple sand teapot. Zisha teapot is a traditional teapot material in China. Made of special purple sand mud, it has good permeability and adsorption. In the process of use, the inner wall of the teapot will gradually attach tea juice and tea fragrance, which is considered to be an important factor to add tea fragrance, so it is not necessary to brush it often, but to rinse it with clear water.