I have several Le Creuset pieces - Dutch ovens and casseroles - that I inherited. They have not been used for 15 years, but definitely were used for non-kosher cooking; it's safe to assume they might have had pork cooked in them. My daughter keeps kosher, and I would like to pass them on to her. Is there a way for them to be made kosher? She's been able to find out the answer for pots made of other materials, but not for the enamelled cast iron of Le Creuset.