Things are busy here. There are lots and lots of posts, and only one admin and two active mods (the other mod is MUCH more active than I am). There is also a team of support people but they cannot move threads out of moderation. So be patient.

I'm not an expert myself on the relationship between SWCG and galvanized metals, but I can tell you from beach experience (just spent a month on the beach) that galvanized metal anything does not hold up well when exposed to salt water, and stainless steel or plastics are the norm for such environments. Even copper piping doesn't stand up well to the salt air environment and that's why beach houses are being plumbed with PVC for cold water and drains and CPVC for hot water. Even outdoor hose bibs have to be made of plastic--as the salt rots everything metallic.

Salt hastens electrolysis, which can eat through most metals other than stainless steel, and even through some types of that as well!

Therefore, I would worry that the salt would be more of a danger to the galvanized walls than the chlorine. Also, many AG manufacturers will void their warranty if you install an SWCG, so that's yet another reason to reconsider.