What's the best product or method for removing the muddy grease on items like the oil pan, frame, and rear axle? I have tried Gunk engine brite degreaser, but it doesn't work that well. Is there something that can be sprayed on and then powerwashed off? I have tried oven cleaner on other things in the past. It removes grease and paint, but tends to rust badly if nothing is done immediately after washing it off.

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