drive home vs plug away

drive home

verb
  • To emphasize (a point) with tangible or powerful demonstration. 

  • Used other than figuratively or idiomatically: see drive, home. 

  • To push something into position completely by force. 

plug away

verb
  • To persist or continue, as with an effort. 

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