Before I got my own WSM and borrowed my friends, I had to clean it before I used it because one of his friends returned it dirty, mold had started growing on it . I used warm water and used the blue Dawn hand dishwashing liquid soap. It worked great. I think the only part I would use oven cleaner on would be the cooking grates with them out of the WSM of course. There is a great section on this web site "Caring for your WSM", there is some great tips there that might work for you. Good luck and smoke on.