I am not certain why you are so sure that you cannot electropolish Aluminum?
If you go to http://www.ep-systems.com/aboutme1.htm you can review one such method for performing this task...
You can not electro polish Aluminum. 300 series stainless steel is the best choice.
Aluminum is not magnetic, it is not effected by Electro Magnetism.
ALUMINUM
with a brush
wash and polish it
Electopolishing is the electrochemical process that removes material from a metallic workpiece. You can use it to polish and deburr metals.
To polish an aluminum plate, start by cleaning the surface with a mild detergent and water. Then, use a metal polish such as aluminum polish or a mixture of vinegar and flour to scrub the plate in small circles until the desired shine is achieved. Finally, rinse off any residue and buff the plate with a soft, dry cloth to bring out the shine.
RUB DOWN WITH 1200 GRADE WET AND DRY THEN IF ALLOWED POLISH UP WITH BRASSO.
To polish aluminum, start by cleaning the surface with a mixture of water and mild detergent. Next, use a polishing compound specifically designed for aluminum and apply it in circular motions using a microfiber cloth. Finally, buff the aluminum with a clean cloth to reveal a shiny finish.
i use orange power in a paste form works great get it at walmart
Equipoment used include the polishing machine, a stainless steel brush, and polish. This process can take a couple of hours.
To polish an aluminum boat hull, start by cleaning the surface thoroughly with a marine-grade cleaner to remove dirt and oxidation. Next, use a fine-grit sandpaper or a polishing compound specifically designed for aluminum to gently buff the surface. Apply the polish with a soft cloth or a polishing pad, working in small sections and using circular motions for an even finish. Finally, wipe off any excess polish and consider applying a protective wax or sealant to maintain the shine and protect against future oxidation.
To polish aluminum to a mirror-like surface, start by sanding the aluminum with progressively finer grits of sandpaper to remove any scratches or imperfections. Next, use a polishing compound with a soft cloth or rotary tool to buff the surface until it shines. Finally, finish by applying a metal polish or wax to protect the surface and maintain its shine.