do one's duty vs drop a chalupa

do one's duty

verb
  • Synonym of use the toilet: to urinate or defecate. 

  • Used other than figuratively or idiomatically: see do, duty. 

drop a chalupa

verb
  • To release feces into a toilet; to defecate. 

How often have the words do one's duty and drop a chalupa occurred in a corpus of books? (source: Google Ngram Viewer )