file off vs scratch out

file off

verb
  • to remove using a file (the tool) 

  • to depart in single file 

scratch out

verb
  • To remove something which was written, by erasing or by putting a mark through it. 

  • To remove something by scratching. 

How often have the words file off and scratch out occurred in a corpus of books? (source: Google Ngram Viewer )