Dog training question.

About a month ago we adopted a 1 year old lab/heeler mix from the pound. Fantastic dog with the kids and wonderful addition to our family. She has a really high prey drive and will give chase to any animal that runs away. Particularly squirrels and rabbits. In the backyard I’m not so worried.

I take her for walks regularly and began leash training right away. She does really well with commands and I even work with her off leash, providing I see there are no immediate distractions. My question is: has a shock collar worked for you in the past? We have never owned a dog this quick before (all golden retrievers before) and I could call our last dogs off and they would return under command with no hesitation. Thoughts?
So to be clear I am NOT a professional dog trainer by any stretch. I will just tell you how I did it. I was raised with Heelers, labs etc. all farm work dogs. I now have a rescued German Shepard. I had never seen anything like the explosion of prey drive she exhibits. Let's just say I was ill prepared! I have been exposed to a lot of guys training with shock collars with mixed results. Not my choice personally. So what I did was get several wraps of leash around hand to create a short leash if you will, put a handful of treats in my pocket and took her to a local park that is just thick with fearless people accustomed squirrels. I would then allow the short leash to become slack and give her the lead to explore. At each squirrel I would get her to hold, and sometimes not. The short leash allowed me to control the 0-60 she can do in nano seconds. After awhile she got to where the treat had more value than the squirrel. Once the squirrel was treed I would release her every now and then to sniff the tree and be her bada** German Shepard self totally not impressing the squirrel. After a few trips to the squirrel park I got the prey drive controlled. But I have to say I have got to be paying attention and do my part. Not satisfied you could ever totally break it.