hairbrush vs shaving brush

hairbrush

noun
  • A brush used in hair care for brushing, tidying, and detangling hair 

verb
  • To spank with a hairbrush. 

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 hairbrush and shaving brush occurred in a corpus of books? (source: Google Ngram Viewer )