custodian vs detergent

custodian

noun
  • a janitor; a cleaner 

  • A person entrusted with the custody or care of something or someone; a caretaker or keeper. 

detergent

noun
  • Any non-soap cleaning agent, especially a synthetic surfactant. 

adj
  • Synonym of cleansing. 

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