How do you use an oven or toaster oven for meat and later for dairy ?
It is controversial is an oven can be used for Milk and Meat. regarding ovens there are poskim who are lenient and allow one to use the same oven for both, however with separate racks, and other conditions. Doing so is far from ideal and should only be done if one doesn’t have a choice. Toaster ovens are pretty cheap and don’t tale up much room, therefore you would be well advised to get separate toaster ovens for milk and meat.