I do not understand all this questioning.
In a class a technique is introduced and then you walk around. I walk over to someone, explain again, show it again, do it with them. They listen attentively (most of the time) and then do it. Nothing has changed while they are sincerely trying to do what you've told them. I've seen this happening time and time again with every teacher. Then you have a choice, you say yes and walk away, you rephrase, you try to come up with an image, ... at a certain point you have to stop since you only succeed in making them nervous and tense. It took me a lot of training to realise this was what was happening with me. Why is he always commenting, I'm doing it. Well ... You go to a seminar and the next lesson there's a talk about it, and someone tells you: ... and you think: hell, I've told you a hundred times. And you shut up, the important thing is that it has been learned. And I guess my teachers thought the same when I told them I made a discovery.
All people need talking, showing and feeling in various degrees to become proficient.
You wrote: 'So the 'dual opposing spirals' are muscular connections inside of the body, and Dan's method, is a way of using these muscular groups.'
The abbreviated original post ran like this:
Dan explains and demonstrates the theory and intent-driven processes applicable to a specific internal skill, e.g. six directions, then students practice them solo and in pairs going forward.
The training model, and the discreet exercises and drills within it, are specific to making physiological changes in the body* necessary for achieving a given set of internal skills -- vs. being technique or form oriented.
Dantien is the mid-section of the body bordered above by the diaphragm and below by the pelvis.
* Dual opposing spirals? Simply put, Dan's and others' methodologies develop these features, which include connective tissues in addition to discreet muscles, and the ability to use them in concert -- for example, in opposition (since they're often in mirrored pairs) to produce extraordinary power expressed on one side of the body while balanced across the body (since both sides of the pair are in play), in addition to the ability to negate incoming force from another person.
Even if you were only summarizing the last paragraph, your summary isn't entirely correct as it leaves out essential information. I think you need the whole quote to get an idea of dual opposing spirals, at least, I don't know what to drop from it.