I believe it's WAD and the Chancellor do not have an effect in friendly counties. But I can agree it's a bit confusing and incoherent, regarding the tooltip that is. I will have to look into it.
EDIT: Btw, as you can see when selecting the "Sow Dissent" feature, the terrain will be green in every other county except your own counties. This should be the indication that you are not to place him in your own counties since there won't be any effect.
EDIT: Btw, as you can see when selecting the "Sow Dissent" feature, the terrain will be green in every other county except your own counties. This should be the indication that you are not to place him in your own counties since there won't be any effect.