Agreed. A smidgeon is much smaller than a dollop, although you could qualify your dollop and take it down to smidgeon size by saying, "...a very tiny, understated dollop." A dollop in the middle range is about the size of a hen's egg. But I wouldn't use dollop with orange juice. I think of dollops as having a form that will hold for a while, and orange juice is a liquid that won't hold its form--unless we're talking frozen orange juice. Now you could have a dollop of frozen orange juice.