Briefly, and off the top of my head, if you are trying to persuade, you want people to only consider the information you present. You are trying to show people a single line of reasoning that leads to an outcome that, by the time you get there, will seem "obvious." It actually works in your favor if they can't keep all of the argument in their head, because then they'll only be focusing on what you are saying right now (and jumping to the conclusion you've compelled) and not looking for ways to examine the veracity or any limiting conditions of what you are saying.

On the other hand, when teaching anything with a conceptual framework (that is, not just showing people how to install Wordpress), it's good to show not only the result, or examples of "truth," but also counterexamples. It's often useful to help define a concept by also saying what it is not. You want people to see all of the evidence and to be able to provide their own reasons as to the conclusion. You are clear, open, and even emphatic about assumptions or limiting conditions (at least to the point where it causes no harm to leave out and would only increase confusion if included).

If you happen to be so lucky as to have a room full of people who all share the same conceptual framework and vocabulary, then standing up and telling a story can also be an effective teaching tool. Mostly, however, we are being introduced to the vocabulary as we are being taught, and multiple channels of reinforcement are very helpful.

I would argue that the kind of persuasion you can get with this technique is most often shallow and short lived. If you fail to make strong impressions, to stimulate emotionally your audience, and to give counterexamples, it's very difficult to create real changes in people's mind. Especially if you are talking about subjects that really matter to your audience.

I agree with your recipe in general, but the main point is that your counterexamples are selected to strengthen your main point, not to point out its flaws.