lavage vs submerge

lavage

verb
  • To wash a hollow organ 

noun
  • A washing. 

  • A washing of a hollow organ. 

submerge

verb
  • To put into a liquid; to immerse; to plunge into and keep in. 

  • To sink out of sight. 

  • To engulf or overwhelm. 

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