Next to bad food, the number-one reason people will not return to a restaurant is dirty washrooms. This fact alone can be used as another way of marketing your restaurant! It's a dirty job but someone has to do it - make sure a member of staff checks on a hourly basis - keep a record that your customers can actually see that you are maintaining them. If your toilets are disgusting then your customers are likely to think your kitchens are also of a similar state. What are the chances of a customer coming back if your washroom is a state?