Stomping slave's head into the water

Water Boarding! Mistress Bianca has prepared a quite special punishment for her slave Joschi in the chamber. Joschi must kneel on the ground, fastened to its collar with the leash. In front of it a pot brimfully with water filled. Bianca pushes it its head till it now again and again for seconds it bears hardly more under water. To some gateways already Joschi is throroughly exhausted and struggles for air.