Incidentally, some of my friends carry homebrewed sprays in pump spray bottles. I would strongly advise against this. It exposes the user to lawsuit. A liability attorney could make a case against homebrewed sprays -- ammonia, vinegar, alcohol, wasp spray, etc. -- as being deliberately cruel and intending to inflict permanent injuries on a "harmless pet." And in some cases it is reckless to mix chemicals and ingredients without understanding the risks of combining ingredients -- ammonia and bleach is one example.
Stick with commercially made stuff.