That's the cool part about chemistry, when used in this synthesis the dichloromethane becomes a whole new (presumably safe, but we'll see what further testing turns up) molecule. Sodium is explosive and Chlorine is highly corrosive, but combine them and you get regular old table salt. Just because a reagent is dangerous doesn't mean the products it creates will be.
Edit: I just did a little research and it looks like 3,3′-Diindolylmethane (DIM) is safe for human consumption. It's already sold as a dietary supplement. It's marketed to help with metabolism of estrogens but we all know how "trustworthy" the dietary supplement market is.
It would allow engineers to create glass panes for windows that not just darken on demand, but selectively filter certain wave lengths of light. The windows could filter out infrared light while allowing visible light through, which would keep buildings cooler without eliminating natural light. The compound, tungsten oxide hydrate, can can selectively absorb different wave lengths of light depending on the current and amount of lithium ions applied to the material.