We recommend using a stainless steel or enamel pot. Aluminum pots can also be used, but the aluminum can become scratched and pitted from the salt in the dye so using an old pot you no longer care about might be the best course of action in this case. It’s always best to keep containers for dyeing separate from those used for cooking. If you must use a container that’s also used for cooking, it is recommended to clean the container with chlorine bleach or a powdered cleanser after dyeing.