I recently spent a very satisfying afternoon giving my pots and pans a good clean. Not the kind of clean you give them every day, but a good old scrub and polish to get them shining again.
You will need a non-scratch scourer for this, some baking soda and hydrogen peroxide from the chemist.
Simply make a paste of 1/4 cup Green Goddess Premium Baking Soda and enough hydrogen peroxide to give you a workable paste.
Apply this to your dirty pots, pans or baking sheets and let it sit for two hours.
Come back and give them a good scrub. Finally wash well with soapy water and dry.