As someone who designs a lot of dissimilar metals into buildings, I have to say that I think the whole galvanic corrosion thing is overdone where you're talking about things other than ships. Most of the studies and quantification are done for dissimilar metals in a good electrolyte (seawater).
Steel wool particles will rust however -- nothing to do with their being embedded in aluminum -- and that's unsightly. In building construction projects, it's sometimes a problem that an ornamental metals fabricator who's clueless will finish stainless steel using the same tools used for carbon steel. Then the "stainless" will rust just like carbon steel; it's not a pretty sight! Again, this has nothing to do with the dissimilarity of the metals, just that the (very thin but effective) chromium oxide layer that protects stainless steel is prevented from forming continuously over the surface, by the presence of particles that are carbon steel, without the chromium content that enables the oxide to form.