Rinse the metal areas with a hose. This will get rid of any debris that may scratch the metal.
Mix 1/4 cup dishwashing liquid and warm water in a bucket. Use a soft brush to wash the metal in round, circular motions. Begin in one corner until you reach the other side. The circular motions will help prevent scratches.
Mix 1 part baby powder with 2 parts milk. Use a smaller soft brush and brush the mixture over the metal. The baby powder and milk mixture will help neutralize any alkaline deposits left on the metal.
Rinse the galvanize metal with warm water to remove any leftover soap suds and milk mixture. Use a microfiber cloth in a circular motion to dry the metal.
Dip a clean cloth in the metal wax and apply a light layer to the metal to help protect it from scratches and oxidation in the future. Use another dry microfiber cloth to buff the wax.