Kinda hard to get chloride poisoning in a reef tank or the ocean when the chloride level is ~ 19,000 ppm and the Red Sea 21,000 ppm . He is talking about fresh water tanks or maybe chlorine and not chloride.
As far as build up yes to a degree that is why one should do 35 % waters / month.
Water Changes in Reef Aquaria
http://reefkeeping.com/issues/2005-10/rhf/index.php
What are these web companies so we can look at them ?