Did you see the movie GREMLINS - never ever get it WET, it is guaranteed to split if you get it wet !
If you get it wet, or are using it for the first time.
You should put it in a COLD oven at 170C (MED heat) for ONE HOUR to dry it out before you use it.
TO clean it, use a metal scraper/spatula and a damp scour pad, but never get it WET.
It will get some stains/discoloration with use - it is ok.
Never had a problem with mine, used it at least 50 times over the last year.