cacolet vs litter box

cacolet

noun
  • A single litter mounted on a pack animal. 

  • One of a pair of chairs or litters mounted on a pack animal (horse, mule, camel) 

litter box

noun
  • A box used to provide a soiling area for (usually) pet cats, generally filled with kitty litter, sand, clay chips, etc. 

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