Dorothy bag vs keister

Dorothy bag

noun
  • A woman’s handbag gathered at the top by a drawstring whose loops are used as a handle; traditionally used by bridesmaids to carry confetti 

keister

noun
  • A suitcase or satchel. 

  • The anus or buttocks. 

verb
  • To conceal something in one's rectum 

How often have the words Dorothy bag and keister occurred in a corpus of books? (source: Google Ngram Viewer )