dong vs knock into the middle of next week

dong

verb
  • Of a bell: to make a low-pitched ringing sound. 

noun
  • A dildo, specifically a synthetic anatomical replica of the penis. 

  • Onomatopoeia for the ringing sound made by a bell with a low pitch. 

  • A submunicipal administrative unit of a city in North or South Korea. 

  • A penis. 

  • The currency of Vietnam, 100 xus. Symbol: ₫ 

  • The currency of South Vietnam, 100 xus. Symbol: Đ. 

knock into the middle of next week

How often have the words dong and knock into the middle of next week occurred in a corpus of books? (source: Google Ngram Viewer )