foment vs work into lather

foment

noun
  • Fomentation. 

verb
  • To incite or cause troublesome acts; to encourage; to instigate. 

  • To apply a poultice to; to bathe with a cloth or sponge. 

work into lather

How often have the words foment and work into lather occurred in a corpus of books? (source: Google Ngram Viewer )