I dare you to look at the underside of the handle to your dishwasher.
Maybe you're lucky and someone in your household has thought to clean it in the half decade or however long you've had your house, but I, alas, have no one who has lived with me who would clean such a detail aside from myself, and I only just noticed it. Ew. We are selling the house soon and when we do it will have a much cleaner dishwasher front and handle than it did half an hour ago. As an aside, they should really make dishwasher knobs easily removable for cleaning like they often do for stoves and ovens. The surface of the handle that glides over the body of the dishwasher as it locks and unlocks is likewise almost impossible to get to.