Why would you want to remove the anodising? This has created an inert but slightly porous surface, properties ideal for paint adhesion. You will find all architectural aluminium is anodised prior to painting, generally not needing an undercoat. Strip the anodised layer, and the aluminium will instantly commence forming a reactive oxide layer which the paint falls off.

Certainly would not be using Alodine, not nice, when we have refinished anodised spars, preparation was given to the failed areas, i.e around penetrations and fittings, but where the anodising was good that was left and just degreased, after all if it hasn't failed you will not find a better substrate. Bare areas were acid etch primed, unfortunately that too has disappeared due to health implications and then the 2 pack high build and finish coat. The primer now days is the difficult part, none appear to stick that well, I assume thats what has driven the move to abrasive blasting to give the paint a key, don't think I would been overly keen to do that to a mast.