You can only put off corrosion for a period of time.
So with that being said. anodizing works well, hard anodizing is even better.
I don't believe passivization works on aluminum the same as it does for Stainless steel (which I think what passivization is for) Although from what I know (which is very little) of the passivization process, anodizing is similar in that it runs an electric current in the metal changing its surface characteristics.
I live by the beach in CA and aluminum just doesn't survive with Any coating I've tried. Not familiar with Desmut process.
thats my 2 cents...hopefully someone with more information chimes in.