All I know is when RAlmaroad and Greendoctor give advice, you can be sure its good advice. Roy knows Centipede for damn sure and Greendoc knows his stuff as well.
If they say that there's a problem with chlorine content with the use of potassium chloride, I believe them. From my own personal experience, I know Centipede is touchy about a lot of things so a "chronic" problem such as this wouldn't surprise me in the least.
"The Poor Fish" circa 1930's: The Poor Fish wouldn't have been caught if he'd known enough to keep his fool mouth shut.