Clean/dirty lockers normally have two or three parts within the locker. One part is meant for dirty or clothes that are worn, and the other side for clean clothes. These lockers are meant for hospitals or other medical workplaces where it is useful to keep work and personal clothes apart to reduce the risk of infection. These lockers are also useful for factories where work clothes can become dirty and it can be very useful to keep them apart from personal clothes.
Rebecca, I remember a previous post that a visitor found storage at the bus station, so I called to see if still available, and it is. Lockers are $3 for the first hour and $1 per hour after that. It's difficult to find storage short term because of security/liability, esp. since 9/11. If you are staying at a hotel, they will often keep your luggage for you short term.