This may seem like a weird question, but did you used to smoke or are you a smoker now?
My friend had this problem. Her fingers were literally bleeding, and then she got going on sucking the blood as a habit. It was getting a bit obscene.
Try wearing gloves. Yes, it will look silly, but it worked for her. I bought her a box of rubber medical gloves. People would see her with the gloves on, make a lame joke, and it would remind her of what she was trying to accomplish.
Other than that, yeah , the gross tasting stuff might work. If you are truly persistent though, like my friend, you may eat your way through it.