Hi There,
The worst thing in the world you can do is polish your stainless or alluminium with any "metal polish" that contain abrasive grit.
The whole purpose of electrically polishing stainless is to get the surface super smooth so that there are no microscopic scratches where salt can accumulate and start the corrosion process. Google search "tea staining of Stainless steel" for more information.
I import an inexpensive product called Poli-ox that will chemically clean and protect your stainless and alluminium without the elbow grease associated with polish
It will also remove rust and other stains from gelcoat with minimum fuss.
After cleaning your alluminium, protect with Allugard made by Rupps, the outrigger people.
We also import Poli-glow Fibreglass restorer for older boats, which is a once a year application requiring no buffing.
All these items are available ex-stock from Norbolt in Richards Bay 0357891243