Need an active spoofing campaign delivering misinformation, with the objective of preoccupying any urban refugee three days. Leads pointing to federal assistance goodies away from your location might suffice—a federal assistance rope-a-dope? Sufficient water and food deprivation should effectively check any mob’s capability to ransack the countryside.
That is a great idea, but you gotta get close enough to them, in that critical timeframe to post the signs. Unless you are going to risk posting them within a mile or so around the neighborhood.