hot tub vs lavage

hot tub

noun
  • A large tub, often situated outdoors, filled with hot water and used for communal leisure bathing. 

lavage

noun
  • A washing. 

  • A washing of a hollow organ. 

verb
  • To wash a hollow organ 

How often have the words hot tub and lavage occurred in a corpus of books? (source: Google Ngram Viewer )