pocket pool vs self-gratification

pocket pool

noun

  • The act of manipulating one's genitalia through a trouser pocket; masturbation. 

  • A variation of the game of pool. 

self-gratification

noun

  • Masturbation. 

  • Self-satisfaction. 

How often have the words pocket pool and self-gratification occurred in a corpus of books? (source: Google Ngram Viewer )