Hydropathy, or the water cure, was a 19th-century health reform movement and treatment popular in Europe and the United States. Patients soaked in cold or hot baths, took showers, were wrapped in wet compresses, sheets, belts, or special wet dresses, drinking copious amounts of water, and sometimes water enemas. This image from Water-Cure for Ladies (1844) illustrates some of the methods used.
To learn more about the history of medicine and questionable cures, see Discovering Quacks, Utopias, and Cemeteries