knock on the head vs set aside

knock on the head

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

set aside

verb
  • To disagree with something and reject or overturn it. 

  • To declare something invalid or null and void. 

  • To leave out of account; to omit or neglect. 

  • To separate and reserve something for a specific purpose. 

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