Grease is harder to clean out. First remove as much as possible manually (shop towels, etc.) Then use hot water or steam to liquefy and float the grease to the top of a water layer, let it cool and scoop it off. Then use liquid Tide laundry detergent in large amounts with very hot water to scrub the rest out.
Believe it or not, they use the equivalent of liquid Tide and steam to extract the last bits of crude from spent oil wells.