I haven't really tested this as it seems kind of impossible to test, but wouldn't making zombies turn into ice and explode around George damage him? I'm fairly certain those blasts can one kill a non-damaged nearby zombie in higher rounds as a comparison to the mount of damage it could do to him if targeted multiple times. I'm sure everyones done it at some point, but has any group made it to a fairly high round, gathered by quick revive and just sprayed those suckers? With maybe one or two people herding them around George every once in a while?
And I know this isn't a lot of damage, but think about it in terms of the whole session... if you do it as much as you can, he could possibly die quicker when using non-pap weapons...
Who knows, maybe this is why you don't get points for shooting him (other than the 10 before he gets pissed), cause you get a lot from spraying the (insert my name here)es around him.