A no, no

[Bruce]

Don't use chlorine tablets in your strainers to keep cooling systems clean.
Chlorine is highly corrosive and will attack just about anything as the gentleman who called me to price out new cooling systems on his engines at a tune of 6k found out.

Says an old timer told him to do it after he complained on the dock about growth in the cooling systems a year ago.

If you get some tip from another boater, ask around and check it out before diving in head first.