confess vs open one's mouth

confess

verb
  • To disclose or reveal. 

  • To hear or receive such a confession of sins from. 

  • To acknowledge faith in; to profess belief in. 

  • To unburden (oneself) of sins to God or a priest, in order to receive absolution. 

  • To admit to the truth, particularly in the context of sins or crimes committed. 

open one's mouth

verb
  • to speak 

How often have the words confess and open one's mouth occurred in a corpus of books? (source: Google Ngram Viewer )