I agree that the hot water would do a great job, when I worked in the meat industry, we use caustic soda flakes. Steam pressurized hot water and air pressure all out of the same silicone hose would cut any grease including the fat cells in your skin. I don't think your pressure washer will survive.

1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy