chat shit vs slag off

chat shit

verb
  • To untruthfully speak of another in a belittling, deprecative, slighting manner, either in person or in absentia. 

  • To talk nonsense or to lie. 

  • To have a casual or meaningless conversation. 

slag off

verb
  • To talk insultingly to or about someone or something; usually one who is not present. 

  • To purify by melting and removing slag. 

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