Do we have to clean properties before we leave?

It is stated in the Terms and Conditions that it is required that the Guest leave the property in the way it was received, in a clean and tidy manner upon departure. This includes washing dishes, emptying the dishwasher, cleaning the BBQ, sweeping the floor and taking all rubbish out of the house and putting the bins out on the curb for collection. This is to avoid excess cleaning costs.