Yard work has decent IP benefits, but spear and pole shaking is better.
I think the best stuff comes from solo and then paired training with someone who is developed themselves for a plethera of reasons. Kata is kindergarten level stuff for IP/aiki-which elbow power is an expression of- that will forever be limited due to the limitations of that venue. IME, it actually prevents serious development.
Next time you're in town we need to talk about that. I picked up a pole per your specs. I can do a bit, but I'm sure the issue here is one of form at this point so I don't spend much time at all working on it. Since it also makes my back flare up later. So next time you're in town I hope you'll have time to cover that in a little detail. I'll even bring my "Lowes Hardware Martial Arts Training Pole"
The wife saw that sitting outside. "Now what the *hell* is that for?" So I told her. I'm outside beating a tree with a bokken and jo, rubber tubes here and there, me pushing on the door jambs, me having the kid randomly try to push me over (think Kato in the Pink Panther movies -- it's fun having a kid). Now that I think about my wife walks away from me a lot with that head shaking thing.