dap won't help with that because you actually want her to refocus, not relax...it would be like giving you valium and asking you to listen to someone.....
I am not the best one to tell you about loose lead walking because my two are horrors for it, mainly because we don't do it a lot. One of my two litter brothers can be managed reasonably well but the other goes into la la not listening mode. They are wei cross GSP and yes, the hunting instinct is strong. I manage him by using a figure of eight headcollar and as well as stopping him pulling so hard, it also seems to help him to pay a bit of attention to me and not pretend that i don't exist lol. can I suggest that you practice walking nicely on a lead in boring places like around the house and garden, just a few steps then praise and treat (use the clicker) and while you are doing that, use a different lead and collar (maybe harness) than the one you take her for exercise in so she associates the new setup with the new training. Once she has it nailed in the house then start short walks outside the house, maybe only 10 steps to begin with, in the new setup and as she gets the hang of it, gradually phase out the old collar that she pulls in. You can also do "look at me" exercise with the clicker, first when she is still then walking beside you, around the house and garden first, then in the most boring place that you can think of outside the house, building up to the most exciting places. Extend the duration of the time that she needs to focus on you from seconds to half a minute and so on.
I hope this helps...is she your avatar?