Once the distraction and "ouch" didn't work well (consistently) for us, I just did the "walk away and ignore" thing. They aren't meaning to be brats (although they are and it hurts); they just want attention and are trying to get settled in to their new surroundings.
Jax really did just want attention, and once I started walking off and leaving him alone for a bit after nipping, he quit trying to get his attention that way. I never really felt comfortable giving him a physical correction (holding their snout or even spraying with something) that young because I don't know that he would have connected it to the biting, and I definitely didn't want him to associate unpleasantness/discomfort with me before he really (100%) knew what he was doing wrong. If he started jumping up and trying to nip my hands, I just walked right by him and acted like I didn't notice him (sometimes I would just say very evenly "no bite.")...I'd shut the baby gate (or whatever barrier there was) and re-enter after a minute or so. If I walked in and the same thing happened...same thing over and over again. Once he associated that nipping with no attention, he just quit trying. I did always have acceptable things for him to chew. It is tedious, annoying, and seems like it takes forever, but it really does get better. Jax is my first Dobe, and I have just learned most things by trial and error combined with advice I got here. I definitely don't want to sound like I think I know everything, but that is what worked for me.
Unfortunately, when their teething is going full force, you might have to do this again!!...I did, but it only took a few times.