If you're close enough to use a lock on a bandana as a skullknocker, you're well inside the other guy's reaction time. From the demos I've seen, a person in reasonably good shape can cover around 20 feet before another person can draw and bring the gun to bear, and that's from an open holster, not from concealment.Seems to me though that reaching for your back pocket during an altercation in order to produce a homemade weapon is a great way to end up bringing a slung shot to a gunfight.