expurgation vs laundering

expurgation

noun
  • The act of expurgating, purging, or cleansing; purification from anything noxious, offensive, sinful, or erroneous. 

laundering

noun
  • The act, or occupation, of one who launders; washing and ironing. 

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