I believe Steve's theory is that the air injection ports which are plugged actually bring clean air (O2) to the exhaust stream to promote further/more complete oxidation of any unburnt fuel as it passes through the catalytic converter. If this is correct, than any cleaner, such as Techron, introduced through the fuel system will not be effective for this type of plugging.

This hypothesis would explain why there are no symptoms of driveablility problems as the engine doesn't care what you do the exhaust stream after it exits the cylinder (at least not on the molecular level).

Yet wouldn't it be reasonable that one could add some sort of solvent to the line(s) feeding these air injection ports to see if that could reduce the plugging which is suspected?