Graham, I learned from the late Kanshu Sunadomari, Shihan and his protege Hamada Sensei, the word makeseru which at the time was described as giving oneself over to the partner. Later, a conversation with another Japanese student described makeseru as letting the other person take the reins, as in, if we were going to the movies, makeseru would be letting you decide which movie to see, or if I was your boss and gave you an assignment, letting you run with the ball...
Hi Corky. Didn't know that word but like your concept.(s) The first one I see as different to the second and both being valid.
We had one term 'shin shin toitsu' originally which we were taught from various viewpoints and actions. Only later was I to find other terminology like sen no sen, sen sen no sen etc. and find they were what we were being taught under tat one thing. Your first concept to me is like a 'sacrifice' as we would call it, a complete giving of what the other wanted. Done knowingly then although giving exactly what they wanted you found them going exactly where you wanted.
The second concept you give I like due to it's non control factor. We have a saying "it knows what to do". Based on the natural way of things then we apply it to not only the person but the sword, jo etc. It is us who "interfere" which is the problem.
When I say use the bowl there are of course fundamental principles and reasons why of course.
One mind blowing thing it does is it disqualifies someone from using their hands to grip or grab any part of the other person. You have to hold them as if they have water in them, in other words if you tip them whilst moving then you have failed because you will have spilled the water. I have a couple of videos of me doing such but without sound and commentary not many would understand what I am doing. There has never been in my experience one person who wasn't mind blown when shown how to do it no matter what grade or martial art they come from. One of my favourite koshi developement exercises.