usiong pressure washer to remove rust?

Recently I was using a pressure washer to clean a concrete surface prior to some masonry work. In doing so I unintentionaly blasted over some rusty rebar and it stripped the rust off. THat got me thinking - I have an old automobile rear axle that I need to clean up and instead of using a wire brush in a grinder, that I might want to use the pressure washer. I am not concerned with have the surface be a spotless metal (nor am I concerned about the immediate rusting that will take place as the water dries) - only to remove the scale prior to applying a phosphoric acid treatment and then paint. I plan on opening up the diff cover after pressure washer (once the axle asm is dry) to check that no water got inside (other than the vent port or bad seals there should be no entry of water). Off in Google land awaiting your thoughts. TIA.