Instructions. 1. Fill the bottom of the pan with a layer of water. 2. Add the vinegar. 3. Bring the pan to the boil. It should be looking a bit cleaner already. 4. Remove the pan from the heat and add the baking soda. Expect fizz! 5.Empty the pan and scour as normal; if necessary add an extra bit of dry baking soda.6. If there are any super stubborn marks that don't come off with scouring, make a paste of baking soda and a couple of drops of water.. Remove the pan from the heat and add the baking soda. Expect fizz! 5. Empty the pan and scour as normal; if necessary add an extra bit of dry baking soda. 6. If there are any super stubborn marks that don't come off with scouring, make a paste of baking soda and a couple of drops of water.