soft-soap vs turn someone's crank

soft-soap

verb

  • To attempt to persuade by flattery or pleasing words; to butter up. 

noun

  • Persuasion by means of flattery or pleasing words. 

turn someone's crank

verb

  • To arouse a person's interest or passion; to excite someone. 

How often have the words soft-soap and turn someone's crank occurred in a corpus of books? (source: Google Ngram Viewer )