a pinch of salt vs disbelief

a pinch of salt

disbelief

noun
  • Astonishment. 

  • Unpreparedness, unwillingness, or inability to believe that something is the case. 

  • The loss or abandonment of a belief; cessation of belief. 

How often have the words a pinch of salt and disbelief occurred in a corpus of books? (source: Google Ngram Viewer )