Make strict rules for all of them. As another commenter pointed out, the wifi-connected clothes dryer could be used in an attack to take down the power grid by

Make strict rules for all of them. As another commenter pointed out, the wifi-connected clothes dryer could be used in an attack to take down the power grid by having many of them switch on at the same time - causing a network overload. Don't try to predict potential avenues of attack. Make strict rules for all IoT devices.