pour oil on troubled waters vs twist the knife

pour oil on troubled waters

verb
  • To calm, appease or quieten a person or situation. 

twist the knife

verb
  • To deliberately do or say something to worsen a difficult situation or increase a person's distress, irritation, or anger. 

How often have the words pour oil on troubled waters and twist the knife occurred in a corpus of books? (source: Google Ngram Viewer )