Alodine is sealant for aluminum and NOT a cleaner. The product that will do the job without fail is called Alumiprep 33. This will take an aluminum surface down to a pure state, which can then be painted, anodized or alodined.
One source is here:http://www.aircraftspruce.com/catalog/cspages/alumiprep.php
This same site sells Alodine as well. Alodine is a surface preparation that stabilizes the aluminum and prevents surface oxidation from occurring at all. Alodine 1201 formula gives the yellow finish most people think is cadmium (Most times it isn't cadmium on Ham gear; an urban myth. And if cadmium is used it's only on steel chassis. Mil spec gear is a different thing where MFP varnish is often used, or anodizing like on the R390a chassis parts.) Also, Alodine 1101 formula is a clear version. Alodine should be applied immediately after rinsing off the Alumiprep, before the aluminum oxidizes.
Now this stuff is mixed into a solution, liberally applied to the surface and then rinsed with water. It will remove all the corrosion and the aluminum will look as new.
Here's a photo of a chassis for an 75A-2a that received this treatment that is currently being restored and finished up in my shop. I never use an abrasive since none of these chassis had the "brushed aluminum" look which you will always get using a Scotchbrite pad. Once done it can never be removed. To me using a pad just makes it look like a scratched up chassis. This metal prep will make it look like the original finish with very little effort. Here's the image.
Here's another image which shows how perfect the surface comes out on all the aluminum parts. This image shows a natural aluminum with no Alodine used, many days after the cleaning process was done. (BTW ... How do you like my Collins spec lacing on the new harness?)
BTW ... If used in solution, it will not remove silk screening on the chassis. Also if you look at the aluminum IF/RF transformer covers the lettering is intact. These also received the same treatments and look as if new with all the lettering. Alumiprep is designed to only chemically react with aluminum & aluminum oxide, as well as other oxides to a lesser degree. This chemical is somewhat acidic and you should use gloves and eye protection when using it.
I have not found a better way to bring back the original finish on aluminum chassis than this product. When both products are used, this preps aluminum for painting extremely well. I use this on R-390a front panels, after chemically stripping the old paint and before applying the chromate primer. No scrubbing or rubbing is really required with this stuff. In fact a gentle hand is preferred since the process is occurring at the molecular level. Hard rubbing will scratch the surface and actually slow down the process. I use a soft natural hair paint brush with the Alumiprep and rub liberal amounts of the solution around gingerly and then rinse & repeat until all the marks and oxidation is gone. Don't let the stuff sit in place, keep moving the stuff around on the piece. Same with the Alodine.
Scratches get hidden well since they are totally cleaned as well and sort of disappear.
BTW, since this product removes all the oxides and leaves a pure aluminum surface, it is interesting to watch the aluminum surface form a surface coating of oxides which it will do in a very short amount of time. Aluminum oxidizes very quickly, but once that surface coat forms it slows. It is because of this it is important to dry the surface quickly after rinsing with water if you chose not to use Alodine and leave the pure aluminum. It spots up easy due to the higher oxygen content in water droplets and the aluminum oxidizes at a different rate under the drops leaving spots.
Ok ... I just gave away one of my trade secrets!!