When Dumbledore is trying to drink the potion and the Inferi keep coming up the hill and dragging you into the water, is there a way to keep the Inferi back and stop them from dragging you down the hill? 
So far I am only able to grab a drink of the potion, then wait to be dragged into the water. This means it takes me a while to drink all five cups. Can I hold them back in any way so I can drink them faster?