we have a baby york who loves to nip, nip nip... so someone told us to get a tin can and put some beans in it. seal it up , then if he nips again just shake it.. then say no bite!!!.well guess what? it really works. he stops !! it scares him and he stops instantly. so now he looks around for that can, if he sees it his whole attitude changes!!! He can be pretty stubborn but this is one thing that works well!!
When he nips, stick your finger (make sure your fingernails are cut so you don't hurt the pup) down his throat to make the dog gag. He will quickly associate nipping with a nasty gagging feeling and will not nip you anymore. This worked well with our Shih Tzu. Even now that she is 5 she will play with our fingers, but never nip them... This, btw, should never physically hurt the dog, only give him a bad feeling! So, don't let your kids do it, unless they are a bit older.
I totally disagree with sticking your fingers down this puppies throat....I mean puppies nip and bite that is natural for them and they have to be taught in a positive way not too. That would be like someone sticking their finger down a childs throat everytime they said something wrong....Very bad advice.