We recommend cleaning your teapot with just water. Just throw the tea leaves out soon after you have finished using them. Rinse the pot until there are no more leaves in the pot. Wipe dry with a clean cloth, and leave to dry until next use.
Over time your kyusu will develop tea stains with regular use. These brown color stains are fine and expected, and they will not hurt the character of your tea. (Each of our kyusu is meant for use with tea only.) If you use your kyusu to brew other teas besides green teas it may eventually develop an aroma of those other teas. This is especially true with fragrance teas, or teas (tisanes or herbal teas) that are made not from the tea leaf.)