freshening vs stimulation

freshening

noun
  • The act by which something is freshened. 

stimulation

noun
  • An activity causing excitement or pleasure; the act of stimulating. 

  • A pushing or goading toward action. 

  • Any action or condition that creates a response; sensory input. 

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