The main problem, I fear, with employing a knife, even as a non-lethal weapon is that, unless you get a jury made up of people who watch "The Best Defense" or any of "The Pincus'" videos, they're going to hear that scary "k-word" and hear NOTHING about the way in which it was employed.
You must remember, juries are made up of people who aren't clever enough to get out of jury duty.
Personally, I like Bogan's approach.
