The kitchen is appliance central in most homes, and we aren't just talking about the big stuff. Your garbage disposal, range hood, dishwasher, toaster, coffeemaker, food processor and other appliances will all work more efficiently when they're clean. Efficiency means longer life. When a vent or filter is dirty, an appliance has to work harder to do its job. It will usually work hotter, too. That means a shorter useful life for that electric knife or electric potato peeler than if you'd kept it clean. Will a little dust or grease destroy all of your countertop gadgets? No, but the effects are cumulative, and prolonged neglect will do more than make your appliances a little sticky and unsightly.