No, can not open the jaws whatsoever.
Stingers (personal 'tazors that use pain compliance rather than interrupt the nervous system that the police use) will NOT work.
No water hose, hitting over the head with a big rock, kicking, hitting with a stick or any other blunt trauma force will work.
There is a video that shows a TRAINED police dog method. I have a neighbor with several incidents where the pitts were locked jawed through the fence. and it seemed to work. Used a large metal chain, because any small leash would probably break.
Stand behind dog, put your legs on the dog's hind hips and hold tight with your legs. Wrap chain around neck of the dog and choke him out. This worked when the other dog was behind a fence. If have two pitts in the open then call animal control first, remain safe inside or away and let them fight until tired out.
let me see if I can find that video again .... nope can't find it. It was an IDF training done indoors which appears to be a children's school class room. The trained dog, trainer had a 'victim' in protective gear, and was not given the release command in order to demonstrate. It was in English.
Here is the Dog Whisperer video. https://youtu.be/DxImB7UQPG8 where he pulls the dog up, he had other people doing same on the other dog, but if you see he is holding the dog by it's collar which is a type of choke out. But when have a loose dog with no collar then going have to improvise to get a choke hold onto him and since we are not trained STATSI then the rest of us have to get a rope, belt, to choke out attacking dog. I could not do what the dog whisperer did, because unable to lift a 90 pound dog off the ground and onto it's hind legs like he did on this video where the dog was still a puppy pitt.
This other guy use a stick which no way in Hades I would try to do because too scared to put hand near dog's mouth but he does show you the legs on the hind position and tell you what NOT to do. https://youtu.be/KfMVH4wY5Pg
Hope this helps. Sorry about your dog. I know how freaking scary it is and very upsetting. Hope your dog gets better.
Of course the pitt bull;s owner is liable for the vet bills of your poor dog.