Yikes, I really don't think this would help much. It would drive me nuts. When Hannah was 3 or 4, she started biting her nails, I went to Walmart, found some nailpolish near the pharmacy with cayenne pepper extract and it worked wonderfully, in a week, no more biting her nails.
[Please don't think I'm a mean mama....I did paint my own nails with it and it was just enough of a bitter taste that you didn't want it by your mouth!]
I haven't been painting lately, unless you call painting a swatch on paper that I'm scrapbooking with....but I have good intentions. I want to paint on canvas again.