Cut eggplant in 1/2-inch slices; place in bowl in layers, sprinkling each layer with salt. Let stand 30 minutes to drain excess moisture; dry on paper towels. Mix egg with 1/3 cup water and flour. Dip eggplant slices in batter, letting excess drip off. saute eggplant, a few slices at a time, quickly in hot olive oil in a skillet. Combine seasoned bread crumbs with the Parmesan cheese. In crockpot, layer one-fourth of the eggplant, top with 1/4 of the crumbs, 1/4 of the marinara sauce and 1/4 of the Mozzarella cheese. Repeat to make four layers of eggplant, crumbs, sauce and mozzarella cheese. Cover and cook on LOW for 4 to 5 hours.