If they’re just using the word “chemical” as an arbitrary word for “bad substance”, you have the situation I already described: the word isn’t communicating anything useful.
But in practice, someone who claims that they don’t want chemicals in their food probably doesn’t just mean “harmful substances”. They probably mean that they have some criteria for what counts as a harmful substance, and that these criteria are based on traits of things that are commonly called chemicals. When you tell them “wait, water and salt are chemicals”, what you’re really doing is forcing them to state those criteria so you can contest them (and so they can become aware that that’s what they’re using).
I think Cade Metz fails to qualify for those things. I don’t think he is trustworthy, quotes accurately, or is truth seeking. And I certainly wouldn’t give him any quotes.