I'm curious, for those of you who don't advocate strong static attacks, how do you approach exercises like kokyu ho?
In my dojo, we don't do "static" zagi kokyū hō. Instead, we have other exercises that train the same sorts of things, but they are done from shizentai with a live, attacking uke. (For those who think that a soft "wrist grab" isn't a "real" attack, well... my experience differs.)
All of the proper cutting lines found in Aiki(bu)dō can be trained in this method with far less (IME) chance of the student falling into struggling at the point of connection. In addition to cutting lines, dropping weight along a vector, proper posture, relaxing within form, and footwork, the student is also training in targeting, distance, and timing.
If a student is pretty competent at this exercise, I'll introduce a hard grip just to prove to them that - - provided they just move the way they normally do and don't buy into the game pitting their strength and tension against my strength and tension - - the effect on uke is far stronger than when uke is relaxed. Uke's own tension is a weapon against himself. The harder someone gets, the "harder" I relax.
As a contrast, I'll then have them do the same exercise with just skin-to-skin (even finger-to-finger) contact alone. It still has to be real, and uke is still alive and honest.
I just did this very thing a few weeks ago, and both uke and tori sides were quite shocked at just how much easier it was for tori and how much harder ukemi (receiving) was for uke due to his own stored tension.
For me, the trick in dealing with people who grasp very hard is that I don't try to move them. I move me. If I move me in the right way, uke's posture is destabilized. Aiki isn't something I do to
someone, but rather with
someone. There is no "no," only "yes." This realization changed me fundamentally.
A strong static grab is, IME, rather easy to deal with. But when someone knows what I'm trying to work on jockies around, yanking and pulling in an attempt to foil my every move... this is quite different. I generally find this activity to be waste of time and that it trains students specifically to not
do Aiki. All the student learns is that they can't do the technique. As my late friend Stan Connor once said to me, "If all you want to do is prove that I can't throw you and that you can't throw me, we might as well bow off the mat and go get a pizza."
Another issue I have with grabbing hard is that by doing so, I'm actually stopping my feet and coiling into myself (within tooi maai, no less). This type of activity does not occur in my Aikibudō (when done properly... ahem). Since I train to do Aiki 100% of the time (not just 50%), I don't do anything as uke that I don't also do as tori. At my current level of skill and experience, the only difference I can detect between the two roles is intent, initiative, and outcome.
For a bit of perspective (primarily for those who don't know me) I'm not unfamiliar with the "hard static grab" training methodology. I was a student of Iwama-ryu before move back to the US.