dispose of vs knock on the head

dispose of

verb
  • To deal with conclusively with a threat or a difficult situation. 

  • To transfer to another's control. 

  • To get rid of. 

  • To arrange in an orderly way. 

  • To have available, or at one's disposal. 

knock on the head

verb
  • To put an end to; to defeat or frustrate (a scheme or project). 

How often have the words dispose of and knock on the head occurred in a corpus of books? (source: Google Ngram Viewer )