Spice mills cannot be cleaned with water, as the grinding mechanism can start to rust. However, if you still want to clean it, try this tip:
Cleaning spice mills
Rice
Simply fill white rice into the mill, set it to the coarsest grind setting, and grind the rice through. You will see that the spice residues simply stick to the rice!
Photo by Sabine, meinhaushalt.at
Read also: Rice for the salt shaker