I understand what you're saying, but for me, the context here is key. This was not a human woman; this was a supernatural being, called such in the referenced text, who was out to damn a town of people (and move on, no doubt, from place to place until she was stopped). So the references and language didn't squick me, given the given context. I also don't believe Dean would say such a thing in reference to a human woman. He's not encouraging violence against women; he's encouraging Castiel in a fight against an evil being. (Yeah, the article in the line is "a," but he is clearly referencing "the" evil being facing them.)

I'm sorry it squicked you and ruined for you what I thought was a very good ep. But I know that there have been a lot things about the mytharc that have really squicked me that haven't phased a majority of the fandom at all. If nothing else, you can say that this show has something to offend everyone.