If the oxidation is mild and light then you should be able to use an oxidation removal product without acid.
Removing oxidation from aluminum siding.
Then use a regular hose to remove the paint and stripper from the aluminum siding.
This can be purchased in sprayable or paste solutions which are very easy to apply.
Mix one part bleach with one part water.
Scrub the stained area thoroughly.
Rub a generous coat of the soyclean paint stripper on the aluminum siding.
Mix 3 cups of liquid trisodium phosphate tsp cleaner and 3 gallons of water in a large bucket.
How to do oxidation removal from siding step 1.
Scrub from the top to the bottom in six.
A razor blade can remove the rest of the paint if the last two steps do not complete the job.
How to remove aluminum siding oxidation from brick step 1.
Rinse the stained area with a hose to remove large pieces of dirt and debris.
Start at the top and spray downward.
These are simply sprayed or rubbed onto the surface of the aluminum and then buffed up using a clean cloth.