Thoroughly clean the chicken under running water, and remove its skin. Put about a third of the sliced apples in the bottom of the crockpot, then place chicken on top of them. Mix together the beer, water, oyster sauce, soy sauce, sesame oil, and orange peel. Place rest of sliced apples on top of the chicken, then pour liquid mixture over contents of crockpot. Put crockpot on low heat in the morning, then turn to high 6-8 hours later. After cooking on high for at least an hour, remove chicken from pot and serve. Serve with rice, steamed vegetables such as pea pods, and the cooked apples on the side.