With ovens with partial self-cleaning, you spend less time cleaning. That's useful, because you don't have to clean your oven every weekend this way. Hydrolysis loosens the grease and dirt with steam from the walls and the door. At the end of the program, you can swipe it away with a cloth. With catalytic walls, the grease that's on the walls burns. You do need to clean the bottom, door, and racks by hand.