castigate vs pick apart

castigate

verb
  • To execrate or condemn something in a harsh manner, especially by public criticism. 

  • To revise or make corrections to a publication. 

  • To punish or reprimand someone severely. 

pick apart

verb
  • To criticise (especially small details). 

  • Used other than figuratively or idiomatically: see pick, apart. 

  • To overcome by skilled execution. 

  • To review or analyse in great detail 

How often have the words castigate and pick apart occurred in a corpus of books? (source: Google Ngram Viewer )