scullery maid vs washing-up liquid

scullery maid

noun
  • A domestic servant, of lowest status, whose job is to wash dishes and do other menial chores. 

washing-up liquid

noun
  • A form of liquid soap used to wash dishes by hand. 

How often have the words scullery maid and washing-up liquid occurred in a corpus of books? (source: Google Ngram Viewer )