I've used a degreaser that they sell at Harborfreight to good effect. It's cheap as dirt and quite effect.
It costs about $6.99 / gallon and you mix it 20 parts water to 1 part degreaser, spray it on and then hit it with a pressure washer.
Because of the hydraulic oil problem and the fan blowing oil all over the engine bay, I tried installing a hood pad and it would not hold for all the caked up grease on the underside of the hood (even after cleaner).
I used this solution in a garden spray and washed it down with my 6hp pressure washer. It worked well and completely removed all the grease from the hood.
It's pretty strong, to use it as a household cleaner, you need to mix it 150:1.
With best regards
Al
1970 Mercedes Benz 280SL California Coupe
1971 Mercedes Benz 250CE (RHD in the UK)
1971 Mercedes Benz 300SEL 6.3
1973 Mercedes Benz 280CE 4 speed
1973 Mercedes Benz 350SE 4 speed
1977 Mercedes Benz 350SLC
1979 Mercedes Benz 450SEL 6.9
1979 Mercedes Benz 450SLC 5.0
1981 Mercedes Benz 500SLC
1973 GMC LWB Pickup
2006 Adidas Samba