Tackling a lot of things as I move along. Here is a question for the knowledgeable ones amongst us: I need to clean the heat exchanger. I don't want to use harsh chemicals that could destroy the environment or be harmful to animals such as my kids (joke). Is pure white vinegar strong enough to dissolve the build up inside the tubes, is CLR an alternative to muric acid? I hear barnacle buster is good too. What is the general wisdom?