What exactly is in this Raclette, I can not yet say the cast iron must be seasoned. The first impression is that this could be great.
Then something that is portrayed here as a disadvantage: the part can not be cleaned, is often written.
As lovers and cast iron pan-friend blurts out to me a "for heaven's sake!" Cast iron gets aged patina fry - and each time something darker ... and better! Since nothing ever is achieved with any Spülis and degreasers best. Some pans I have actually not paying attention and my wife has the Dinger "classically" washed. Looks clean - there never again shall be liable to Patina - tastes insipid as Teflon - dead pan! Cooks clean such elements in two ways: soak after use for a while in water and a sponge (absolutely no soap - even wrung out - really an extra sponge, can it also be a very expensive) rub until no meat / Russ etc going. more. Rubbing is not a problem for cast iron. Should not soak for days to the well: can corrode the unprotected iron already. If now even thicker Russ cakes are really not come off (which is usually the first few times the case - before a patina plated iron): burn down the next time you use. So: simply turn on the device, long before the visitors arrive, forking out the cast iron plate and just leave a little while idle. As a rule, char now remains completely that were not solvable. Allow to cool and tap the charred parts with a wooden spoon (Ch. Chopsticks, wooden spoon, Fleichwender ...). So to clean clear warm water and / or burning.
The discolouration - that already exist - are simply this and are not a sign of dirt, etc.
Cast iron is such a thing as a natural product in this sense.