I would be very careful with using mayo on your plants...I had read about that many years ago and to 'surprise' my mother one time, I used mayo on her HUGE, potted, indoor tree (I don't remember if it was a rubber tree or a ficus), and it looked gorgeous when I was done. Mom loved it. And then it started to turn brown,lost every leaf, and DIED....She was told it was from the mayo clogging all the 'pores' on the leaves so they couldn't breathe and it killed the tree....I have never put mayo on another plant!
Maybe mixing it with water like Elaine suggests isn't as dangerous...but I might still shoot for the lemon juice myself. I've never gotten over killing that tree of my mom's when I was trying to do something nice. I felt SO horrible!
