Ahaha the story of the left/right hands is a really cool one. I didn't know about those facts, and learning about them is very amazing. In particular:
If you were to instruct the right side of the brain to hold something (with the left hand) and then proceed to ask the left side of the brain why they're holding it.
I was drinking a cup of coffee while reading your post and was actually holding the cup with my left hand. I would have loved to be able to instruct a particular side of my brain to hold the cup and make the exercise with the other side.... I just don't know how to do it (I tried to play the trick with the eyes, but it does not work (at least with me).
I am wondering how Gazzaniga managed to find patients to make his tests and have those tests working. It does not seem I would have been a good patient ;)
Cheers!