Outdoor Shower !!!! Love These idea's! You could even sand & treat closely gapped pallets for flooring, even the walls. The drainage would be easy to do. Pea gravel, rock, or French type that goes verticle if using a shampoo or soap very often. Anything but a 'green product' would then most likely do some vegetation damage.
El Capitan tents and cabins outside Santa Barbara, CA. Perfect weekend get-away! Nearby killer mountain biking, wine tasting, shopping and restaurants AND you get to sit fireside and roast marshmallows.