No offense folks, but why would you advocate buying wasp spray or making up an ammonia solution when pepper spray is legal, cheap, effective and also usable on human targets should you need it? I understand and appreciate alternative solutions and homemade remedies in some situations, but in this case it just seems silly to me.
I would agree that the real issue is people not following leash laws. My situation is the opposite. My dog is not dog friendly at all. He is alway leashed, but when unleashed dogs come to sniff him, its game on. Luckily he is 13 pounds of terrier terror and so i just pick him up when I see trouble coming, but it aggravates me that those dogs aren't on leash. Your dog may be great, my dog is kind of a jerk.
As a sidenote, he has tried to fight any dog he sees including wolfhounds, and also horses, cows, and as of a couple of days ago a camel. Friendliest little jerk in the world to adults and kids (including babies) but not at all tolerant of other beasts. Whatever, he is my buddy and I love him just the way he is.
Here is a picture of him. His name is Auto.
sent from my Galaxy Note II.