If it still doesn't work, try a little vinegar or bitter apple. Again, some dogs acquire a taste for this, so use with caution or it may suddenly seem like part of a game. When your pet pulls a naughty, shake the can. The noise should startle him enough to get his attention and to stop him. Remember to praise your pet when he chooses a more appropriate behavior instead.
Buckle collars are never impossible to escape from.
Choose the lightest chain for the breed and size of your dog. The chain choke should be fit fairly loosely until a correction is necessary. Snap the lead with a swift wrist action when correcting. A chain will make a sharp noise when it snaps. Eventually, your dog will listen for the chain tightening as a tip off to stop pulling when walking.