Look at all the people that were fooled by Helen last summer
There is only one reason that Helen won and it had nothing to do with changing attitudes. It was all to do with lengthening odds.
As she became more and more unpopular, her chances of winning got less and less and the bookies offered long odds on her winning. The smart betters swooped in at the last minute, put stacks on money on her and voted like mad to make sure it paid off.
Regarding KH in the house, I don't think I would find her that hard to live with unless I was the target of her incessant bullying.
However, when she said to Perez 'I'm going to follow you round all day and annoy you, blah, blah, blah...' if I was him I would have said, 'Oooh lovely, my own little pet'. Then I would have walked into the garden saying 'Here kitty kitty Katie, Katie. Come on into the garden with me, come and follow me around' 
She would not have known what to do then. And if she started insulting me, I would have said 'I love it when you talk dirty'
That would have annoyed her no end.
If Perez was annoying me I would just ignore him or walk away and let him get on with it. So far everything is going his way. He gets loads of airtime and everyone is talking about him.
In fact, by telling everyone to not speak to him, KH has in fact put all the attention on him. I think he is smarter than he makes out.