Hydrotherapy has had and has a rationale.
Ahlqvist
J
J
D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D006875:Hydrotherapy / Q000266:history*; D012216:Rheumatic Diseases / Q000266:history* / Q000628:therapy