There are a lot of factors. How much Chlorine? How much chloramine? What is the biology like that you are applying it to? There are probably other factors beyond that. I think the "guy at the store" is making a huge generalization.
If the "options" you are looking for is how to get safe water for organics, then bubble it for 24 hours like mary said, but put a little bit of EWC in there to release the chloramines first.
non R/O water is perfectly fine, provided you know what's in it. For most people in the US, your municipal or city water should be fine. It's not going to kill the microbes once the chlorine or chloramine has been complexed.
Best way to find out if your water kills microbes is to do a mini experiment with some distilled water from the store and some of your local water. I think he's probably just trying to sell you product though.
