Anyone here use a slip lead or martingale collar for daily walks? Luna's walking has greatly improved, ie. pulling, over the past few months of using a prong collar for walks and I feel like we could take a step back on what we're using and have seen a few other people with GSP's using slip leads and occasionally martingale collars. Our dog walker recommended we try a martingale, but I wanted to see what you guys may recommend. She normally walks on a 4 ft. leash. Thanks!