[Help] What's the safest way to stop a dog from latching on to another dog and make them let go.

I just wrote another post about my dogs fighting. One is a latcher and and latched on to the other one. I did the wrong thing and pulled him by the legs while my wife also pulled but that probably made the tear and bit worse. So what are some ways to stop the dog holding on? I heard water works, I didn't try it anything else? via /r/dogs http://ift.tt/2syBkBs