catechize vs test the waters

catechize

verb
  • To give oral instruction, especially of religion; (specifically) by the formal question-and-answer method; in the Church of England and Roman Catholic Church, to teach the catechism as preparation for confirmation. 

  • To question at length. 

test the waters

verb
  • To explore or probe, as before making a commitment. 

How often have the words catechize and test the waters occurred in a corpus of books? (source: Google Ngram Viewer )