scrubbing brush vs shaving brush

scrubbing brush

noun
  • A short brush with stiff bristles, held in the hand, used for scrubbing floors etc. 

shaving brush

noun
  • A small brush used to create a lather from shaving cream or shaving soap and apply it to the face or other area before shaving 

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