Well, I don't see then how it would be possible to even remotely effect the hogykyoku without having to channel its powers then? And how do you explain the Rukia event using this model? I don't really see how that makes any sense.
And I think, one can very well view the hogukyoku as a direct force in that any person who is aware of its existence can direct it into fulfilling one's own desires. I mean, isn't exactly that which Aizen has been doing? But to do this, he had to plan out the events so it would actually be possible. I mean, what would be the whole deal otherwise with the plot so far?