In the videos Brian sometimes carries what looks like a wooden stick with a golf grip. Or is it a narrow flat board? What is that? My guess was a trading aid to generate wind resistance during a swing to help build swing speed muscles. Is this a Tathata training aid? If so, I would be interested in buying one.
He usually carries two things in his drills – either a wooden-shafted iron or his bokken. The bokken is a wooden training sword. He has one drill that he shows in person where after reaching the top of the follow through he throws the bokken into the ground to demonstrate the flow of energy out of the shot.