laundering vs purgation

laundering

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

purgation

noun
  • The process or act of cleansing from sin or guilt. 

  • The process or act of purging, such as by the use of a purgative. 

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