beat one's meat vs flick off

beat one's meat

verb
  • To masturbate by stroking or rubbing one's penis. 

  • To waste time; to engage in an unproductive activity. 

flick off

verb
  • To masturbate by flicking the clitoris with one's finger or fingers. 

  • To insult (someone) by showing them the back of one's fist with the middle finger extended. 

How often have the words beat one's meat and flick off occurred in a corpus of books? (source: Google Ngram Viewer )