Missy says…I used two lice treatments on my hair. Today I am trying to condition my hair because it is completely dry and still a little itching. I researched and mayonnaise is supposed to kill lice plus condition hair….is this true?? The Beauty Brains respond: Can mayonnaise kill head lice? Missy, Missy, Missy. That is […] Does mayonnaise really kill head lice?