A self suckling goat is not a good thing! I know people who swear there is only one cure for a self suckling goat. That cure is a rather final one, and generally isn't a good result for either you or the goat. Trying something on the teats is a good idea, but you have to find something she really doesn't like. A friend of mine used vaseline intensive care hand cream because her goat hated the taste of that and it stopped her. You can get contraptions to go on their necks, or Gillrugs made for a friend of ours, an extension to a goat rug which covered the goats udder and therefore stopped her suckling, but I don't know if they have marketed it.
Beth