Have so get clean again our hob. Of course you have to spend even force, because by itself cleans anything. But containing household detergent or other cleaners I could never remove these extremely stubborn grease stains from the hob. The supplied sponge I can not recommend, prefer to use a sponge with a bit rougher surface, however. I am very happy with it, because the plaster stone for the price lasts a long time in any event.