Looking at the floor of a pizza oven—generally, they’re refractory cement or tile—you’ve basically got a pizza stone right there. What might sell you on a separate pizza stone is how much simpler cleanup is. Using one doesn’t hurt anything and, especially with a mound of toppings, it’s far less of a hassle to clean off a removable stone than the oven floor. Cast iron cookware is also a great option for cooking deep dish pizza and making other dishes in your pizza oven.