April's Waterwell Journal has an article about a product "BoreSaver Ultra C". It seems to show favorable results in combating bacterial iron and claims it is less corosive than the usual cleaning agents.
While they are ambiguous about frequency between treatments for a water well (might vary) it may pay to explore as a cleaning solvent for plugged coaxials (or at least keep on our radar).
j

I saw that as well and am patiently awaiting more detailed info in regard to its down hole application.
Eric