"This is a guy who executes people with anti-aircraft guns remember. "
I think if I was to be executed, an anti-aircraft gun, while messy, would be awfully quick.
It certainly beats choking your lungs out on poison gas or writhing about on a wooden pole with half a dozen rounds in your torso. Or how about dangling on the end of a rope?
Whatever we think, the killing business ain't stopping anytime soon, so I would imagine a quick end, regardless of the mess, would be much preferable. I'll pass on being torn to pieces by dogs.