Yeah, the flow looks pretty slow for anything but the strongest flavorings where you
really do only want a drop or two in a whole batch. I hear tell, though (I don't have any of them myself) that you can fit a blunt-tip needle
through the opening, if that suits your mixing style. I don't think they were designed with that intent, however, so it
might just damage the insert just enough that the opening is a little wider and the drops flow a little faster. And of course you wouldn't want to damage a valuable, useless bottle insert, that you don't even use otherwise, like that, wink wink nudge nudge.