The term 'clean fish' refers to a fish that has been prepared for consumption. To achieve this, the fish must first be gutted (3 letters), which involves removing the internal organs. Then, it must be scaled (5 letters), which involves removing the scales from the skin. After that, it must be exenterated (10 letters), which involves removing the gills and other organs from the head. Finally, it must be sanitarycod (11 letters), which involves cleaning the fish with a sanitizing solution.