A.H.
My sister and I were both finger suckers. I can't remember what really stopped us, but I know she tried some sour apple polish that goes on your fingernails. I've used this with my nail biter son, you can find some at CVS and it's made for all natural ingredients. You have to brush it on a couple times a day, but they'll soon associate the bad taste with putting their fingers in their mouth. It could work for you.