ferreting (around) vs scouring

ferreting (around)

scouring

noun
  • The act of cleaning a surface by rubbing it with a brush, soap and water. 

  • Diarrhea. (Now used only of livestock, though also sometimes used of humans into the 1600s.) 

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