Asatru, yes. Sometimes we perceive ourselves as cursed, and end up cursing ourselves in the process. A lot of witches, conjure workers, and the like use this idea to improve their own curses in a way. They're worries can fuel the curse for the caster. Or, the caster doesn't have to do anything at all; they just make the target think they're cursed.
Even in the case of "crossing yourself," a spiritual cleansing, a very stripping one, and a strong protection working would help the person overcome it.
In regards to the question on the poppet, it would identify him in a way. Even if LostHowler couldn't get to him, curses tend to move to the closest thing, stuff around him, until it finds a place to "land". It's still sending it back to the origin, so either way it will leave her.