Yeah it sucks to get moisture between the lenses. Let me guess...the fog is only in the middle of the lens and there's a clear border around it through which you can see clearly?
Leave them in the drying room over night or near a heater (not too hot) with the goggles propped up on their side. Ie. With the little white/black valve at the top so it can release the moisture. The problem is caused by not drying them out properly but this will solve it.