Do the hotels on the Spain My Way itinerary offer laundry service?
Diane since you haven't had any answers, you could call the Tour department. It also will depend on which hotels your actual tour will be staying at which they might not know for sure until about a month or so before your tour. Your guide will do his or her best to meet all your needs! Your other option might be to take your laundry to a self-serve laundromat or one that's not self-serve. Washing in your hotel room sink is also a possibility that's why it's really helpful to have fast-drying clothes!
Rick's Spain 2016 (the 1000-page book) lists a full-service laundromat at the start of each chapter for your destinations. Your tour escort will also have that info, and your hotel may know of one closer to them or have an agreement to collect laundry for such a service. Also, your fellow tour members won't blink if you wear the same clothes more than once.