If you know that a dog is going to bite and you have no weapons, when it opens its mouth to bite, jam your fist as deep and as hard as possible INTO its mouth, then wrap your free arm around its neck and put it in a head lock, and squeeze. In a few seconds, it will start to pass out.
If you're fast enough to shove you're fist down an attacking dog's throat, you're better off picking up a rock and beating the dogs head in.
Injuries from dog attacks are caused exclusively by biting, biting come exclusively from the dogs mouth. It's stupid to put you hands in or near the only part of an attacking dog that can injure you (unless you're protecting your face).
If you choke a dog out and don't kill it, as soon as, it wakes up it's game on all the way.
If this dog is a fear biter/hand biter, the more physical you become with it the more aggressive it will become. The next time this dog is sees a raised hand, it goes from fear biting to full a blown "condition black" attack. Or, the next time someone turns their back on the dog, the next thing they will feel is teeth in their neck. How responsible is it for a someone to physical abuse another person's dog in a kennel?
I've spent a little time in dog shelters, if you get physical with an aggressive dog your running a serious risk of getting bit, if at all avoidable never deal with aggressive dogs alone, and never do it without the appropiate equipment. There's a saying about playing with matches and knives.
If a dog shows signs of attacking make eye contact, take an aggressive stance like you're going to pummel the crap out of the dog, and as angrily and with as many expletives as possible let the dog know he needs to get away from you. These are dogs that haven't made up there mind to attack you, dominance and aggressive behavoir will almost always deter an attack, never break eye contact. Or shoot the dog if it stand still enough for you to safely shoot. If you pepper spray, kill the dog while it's down or get up a tree. Don't hang around.
If a dog attacks you, you're going to get bit, suck it up take it on the hand or leg, either beats the face. Once it bites, shoot, stab, choke or bludgeon the dog, kill it.