TGU’s with a medicine ball, revisited

I posted this a while back and didn’t get back quick enough to followup on the comments, so:

I’d seen videos of people doing TGU’s with no weight at all, just a clenched fist. I thought that didn’t really force you to use proper technique with the weight-bearing arm, so I tried doing them with a medicine ball. I found, since I was unable to hold onto it, I had to be very cognizant of keeping my arm and hand "under" the ball to keep it from falling off.

Long story short, I thought it worked, but all replies were very much against doing so, owing to having the wrist bent back to palm the ball. They felt that it promoted bad technique. Seems to me wrist position–while very important–is the easiest thing to get RIGHT about doing TGU with a kettlebell, so I’m still kinda sold on it.

Anyone have any thoughts?