Another thing to try is to maybe watch him without him knowing that you are watching him, so he thinks he can chew the carpet... and each time that he puts it in his mouth, loudly shake a pop can with a few coins in it. The noise will startle him. If you are consistent, and maybe do this along with the vinegar... maybe pretty soon you can get new carpet. The only thing that I would worry about with the apple cider vinegar is fruit flies. I don't think that white vinegar would do that. Some people will use a little Tobasco, but that may discolor your carpet.