What I would suggest would be to take the sock off of him and give him a toy in his mouth instead we got told to do this when my dog bit as a puppy and it seemed to work maybe it will do the same? also please dont give you dog any rope toys!!! there was a post in the dog chat that showed a poor dog that chewed up a rope toy and swallowed some and it cut up her insides, have you tried a toy made for a bigger dog? like a black kong? there are very strong also a galliath bone is rock hard so you pup cant chew through it, but please make sure they are suitable for you pup so it doesnt damage his teeth, I cant give my dog soft toys as they just chew them up after 10 mins