Pressure washer. If you don’t have one then you can rent one pretty cheap. The only problem with a sponge is that it will get full of dirt very quickly.
the magic eraser would work on getting out the oxidation color after the pressure wash. i use the generic brand for many boating discolorations and they work like, huh, magic!!!
Mild soap, warm water, a soft boat brush, and elbow grease.
You could always try a pressure washer. If not the old fashion way the rag and soap.
Pressure washer. If you don’t have one then you can rent one pretty cheap. The only problem with a sponge is that it will get full of dirt very quickly.
Pressure water.
the magic eraser would work on getting out the oxidation color after the pressure wash. i use the generic brand for many boating discolorations and they work like, huh, magic!!!