Oh boy! Thats stuff is really hard to clean.
Hot soapy water works just fine.
A word to the wise. Keep a bottle like one from Ocean Spray cranberry juice handy, about half full with half water and and half Windex. Drop the freshly fired cases into the bottle and shake a bit. The solution is also good for cleaning the barrel. You can even use just plain water, but the Windex makes it a bit easier.
Paul B.