I just scrap mine and leave it alone. I consider it "seasoning" the stone.

You left it for one hour? Mine heats up in about 15mins.

There is not much you need to do with a pizza stone. Just scrape off any large food particles and find a scrubbing pad to lightly scrub off stone in hot water. Do not use detergent, just hot water. Oil will be left on the stone. The stone is like cast iron, so do not clean it to death. The stone will darken with age, so do not worry.

Excellent, thank you both very much.

Consider it (grease, not soap), "seasoning."

About once a year, we run the pizza stone through the self-cleaning oven cycle. Comes out clean as new and ready to be reseasoned.

as a potter who mkes pizza stones for the family and friends i would advise putting the stone in the self cleaning oven. the oven gets to a temperature lower than the stone is fired in a kiln. the high heat should clean the stone and not damage it. if it has any additions to the stone such as metal or wood then don't do it. but a stone should be able to withstand the heat of a self cleaning oven