hammer home vs ingrain

hammer home

verb
  • To repeatedly or continually emphasise (an opinion or idea) until or so that a person or group of people understands it. 

ingrain

verb
  • To make (something) deeply part of something else. 

  • To dye with a fast or lasting colour. 

adj
  • Dyed with grain, or kermes. 

  • Dyed before manufacture; said of the material of a textile fabric; hence, in general, thoroughly inwrought; forming an essential part of the substance. 

noun
  • An ingrain fabric, such as a carpet. 

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