Have always use a regular knife. I clean fish very fast. Been doing it for 40 plus years. Per side - Perch are 3 cuts and a walleye is 6 cuts if you include the cheeks. I fillet and brother skins and tosses me fish from the cooler. Still have all 8 fingers and boths thumbs - LOL Shape knife and a steel are important. Beer break every 10 perch