It seems for most puppies no response is about the same as encouragement. If you want to change his behavior and he is persistant in continuing the same behavior I feel you have to use a rememberable reprimand. By no means am I suggesting anything abusive but your response has to be enough to get him to stop immediately and decide that it is not worth continuing. I am aware that many behavioralist maintain that your hand or foot cannot be part of the correction but "lifting" him away with your foot is still a measure that works for me. You can also thread his leash through a length of plastic pipe so that you can keep him at a distance where he cannot get to your feet.
The main point here is to create the situation where the behavior cannot occur or to impose a penalty that he remembers and wants to avoid.