slop bucket vs stool of easement

slop bucket

noun
  • A receptacle used to hold liquid waste. 

  • A pail used to hold food waste for disposal, e.g. by feeding to pigs. 

  • A bucket used for urination and defecation: a chamber pot. 

stool of easement

How often have the words slop bucket and stool of easement occurred in a corpus of books? (source: Google Ngram Viewer )