Ya know BobKat, that is not such a bad idea. It would not permanently harm the animal and hopefully encourage him to release!
I have been in situations where I have grabbed anything closest to me and started hitting the dog over the head as hard as I could and it still would not release. This is a horrifyingly frightening situation to be in. the only thing that had any effect on the pitt bull was spraying the dog with a hose in the face. Even pouring a bucket of water over its head did not phase it in the least.

Unfortunately by the time you locate a hose a great deal of damage is done to the victim.
Is it legal to carry pepper spray in Florida?