I thought about it some years ago, but being the cheap-ass that I am, I wanted a way to refill the canister with a pump; that requires the AirZound, or something like it. I haven't invested in that yet.

Of course, NOW, I almost never have dog issues; the last one just followed me to work, never got within 8 feet of me! (Now the one BEFORE that, I foiled by 'out-barking' it, much to my chagrin...sore throat....)