I like the washing machine analogy.
But anything is susceptible to being broken. If break a frying pan, a figurine, a plate, ect., as a sitter I assume I’d be responsible for replacing it. But if the vacuum breaks in the normal course of using it, I don’t think I should be responsible. I have no idea if the vacuum already had problems and using the vacuum to clean the house is something I need to do to fulfill an obligation to leave the house clean when I’m sitting.
The only times I’ve used a homeowner’s car is when I’ve been asked to in order to transport the pet to a dog park or take them hiking. I feel like if a homeowner requested that I use there car, I shouldn’t be responsible for non-negligent damage. But if I asked to use the car, it’s be a different story.
Sure, the homeowner gets the benefit of the new tire, but don’t they also get the benefit of the replacement for a broken plate?