I see that it would probably recruit just about every stabilizer muscle known and maybe a few new ones along the way....lol. My god the rotator cuffs would scream I would think with all that movement.
I think it could be very beneficial, done appropriately.
However this could easily cause an injury as well. Both from a soft tissue perspective but also in overall safety as well. The more you struggle, the more those dumbells are going to travel and bounce around. Could be a recipe for disaster? You'd certainly want to have a real good spot and be using contextually light weight.