It's like those trailers you see offering dog grooming services. So you have a shallow bath structure and a choice of salt or fresh water. You put the turtle in, let the hydrojets gently wash over it, then you rinse and return to owner. I haven't yet worked out how to handle to handle Galapagos Island Giant Tortises yet - probably need a hydraulic lifting platform and or a hoist. Of course you write a smartphone app with GPS and booking - rather like Uber. All mere details ;-)