My way of Ninja
Member
In my opinion the damage occurs only when he hits the enemy with the Jutsu. This is because There was no damage when he actually creates it. He has done it many times without any harmful effects ( 3 times during Kakuzu fight). When he hits the enemy with the jutsu, during the impact, his arm also gets caught up in the blast and gets damaged.hmmm.. Maybe not sure...
So technically if he can throw it, i guess there should be no harm ! What do u think ?