clean off vs efface

clean off

efface

verb
  • Of the cervix during pregnancy, to thin and stretch in preparation for labor. 

  • To make oneself inobtrusive as if due to modesty or diffidence. 

  • To cause to disappear as if by rubbing out or striking out. 

  • To erase (as anything impressed or inscribed upon a surface); to render illegible or indiscernible. 

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