We do the bite inhibition training by the book: shouting OWWWWW like a drama queen at the least little nip. It took a looooong time for our one dog to get it (I'm talking, six months), but now both dogs are not the least bit mouthy. Well, unless you count licking us to death and drowning us in dribble, but they don't nip.
In the rare event that the Pyr wants to pull me away from something he feels is dangerous, he firmly grabs my shirt or jacket edge in his mouth and tugs gently. When I have to give him medication, if I touch his teeth with my hand, he will actually open wider so as not to nip me. The Newf just licks and licks and licks, and when she gets overexcited, she flops on her back and rolls around instead of nipping. It works, it just takes patience.