I have to say, I've never used a dechlorinator.
If you think about it though, leaving tapwater for a day or so is one way of removing Chlorine, (not Chloramines). If you put tapwater in the bottle, and then pipe all the product from the reactor into the water, the Chlorine in the tapwater has got to go somewhere, and through the tank is it's easiest path. I guess the slow release from a small volume is not significant.
A second issue is the yeast. Yeast is alive and you'd think the Chlorine would kill it. Perhaps that is why some people have trouble getting their reactors going?
Interesting thought.