I haven't really touched on that, since I've been trying to keep things clear and (mostly) understandable.
Of course, that's the whole paradigm of Kototama, and the chanting that Ueshiba did was used for that purpose. Basically speaking, I think that he was using it to focus his intent in certain ways, and this worked well for him because of his religious beliefs and background.
For other people, perhaps not so much (it never did much for me). Notably, he discouraged people from joining his religion or joining in his religious exercises, so maybe he understood that it was different for his students than it was for him.
Do you think Ueshiba might have been chanting to reach a natural "high", too? If training sort of affects the mental state of mind, maybe Ueshiba really was feeling like he was the universe. Some people meditating/chanting have said they felt like they had a buzz or that they felt like they were floating above their bodies.
Plus, Ueshiba knew that Horikawa and Sagawa had reached an equivalent level of aiki in their own way, so Ueshiba knew that follwing in his religious foot steps wasn't necessary. But you had to have aiki to ... What did he say ... Aiki makes the religion better.
For Ueshiba, it was Izanami/Izanagi. But, as you have read, he did say that these were contradictory forces working at the same time in a spiral fashion - internally.