If its teaching the pup what the word "no" means that your having issues with then i would advice the following, i have had only one dog, and she is 14months old so i am no seasoned expert but i also had issues getting Daisy to stop doing stuff i didnt want her to do round the house.

When you see her doing something you dont want her to, make a kinda "hup!" sound, dong scream it, the whole sound should only last half a second but make it loud-ish.....maybe not so loud if its a lil puppy. Usually they will jump at whatever they were smelling, clawing, chewing and Daisy seemed to belive that it was the object that made the scary sound. She used to chew the valve at the top of the gas cylinder in my garden but she stopped that using this method. I did try positive training methods but all that taught her is that if shes doing something wrong, and i say no, she has all the time in the world to do what she wishes and above all, she can do what she wants AND get a treat after it.

Anyway, make the "hup!" sound and then when the puppy looks at you or something, in a firm yet loving tone say "No". Will take about a week to get it working solidly depending on how sharp the pup is i guess. Even then smells that Daisy REALLY likes or in the presence of a squirrel, No does not work.

Additional tips, try not to let the puppy figure out that it is you that is making the "hup!" sound, it really works much better if she / he thinks certain object make scary noises when played with.

Hope it helps...