Lots of fun to be had playing around with your brain and a 9V battery!? No. On average a body has about 1000 ohms (wet hand to wet hand) which in my mind divides down to 9mA, 4.5 times the recommended current. 0.15mA reaching your heart will probably kill you. About 15mA/cm² on an electrode will cause tissue damage. So, if you want to experiment with this in a safe manner, get something that will provide only 2mA, no more, no less. And even then you can fuck yourself up easily. Great potential for big laughs.