Easy way is EZ Off oven cleaner and place in a plastic garbage bag. Let sit for an hour or so in tub or kitchen sink. Then rinse, wash with dish soap, dry and replace.
Hi ! I would bring them outside and spray them with oven cleaner , let them sit awhile , then hose them off. If that doesn't get everything off, I would try a steel wood pad .
Here's a link with 5 suggestions:
I just put mine in the bathtub with warm soapy dish soap water and let them soak for an hour or so. You can then take a kitchen sponge with a scrubby side and scrub them off, rinse, and stand them up to dry. They come out like brand new.
Hi Sassy: Make a paste of cream of tartar (the dry stuff) and vinegar. Put it on the grungy parts, let it sit about 10 or 15 seconds and wipe off with a scrubbing pad. Rinse in warm water and that should do it. Non toxic and no smell:) Good luck