After reading through the post and almost all of the comments it seems like the real target that is trying to be cured are the Lack of Brain or bot votes. Although talked about a great deal there is one solution for self voting.... remove it again.

If you were told there was a way to reward real PoB votes over bot votes with a slight inconvieniance to the user, while offering additional transaction rewards to non-top.twnety witnesses, would you be interested?

Here's my year old idea.