Sudsy Amonia in a squirt gun. The dog will come unglued when hit in the eyes. It works paperboy tested. A nice chunk of gas pipe say 3/4" size about 2 and a 1/2 ft long velcroed to the frame some place to be used as a club works too, also paperboy tested.
A swift kick to the head work too but not with out risk, damm dogs never expect to get a boot to the head.
Mace works too.
Joe