Flame throwers. Chain saws. Machine guns. Sherman tanks. Thermonuclear devices. All of these can in one way or another assist in defending against zombie attacks.
But I was walking down an old road in Colma and came across a small shack. I slowly looked inside and saw an old man sitting with his back to me. I was worried he might be an undead but without turning his head he said: "Welcome grasshopper. You seek ways to kill those that are already dead."
I stuttered "Y...y...yes. Can you help me?"
He was silent. But he lifted one long finger and pointed towards the wall. Hanging there was an ancient manuscript:
You can validate your puzzle solution with certitude.