At the end of Crown of Swords, Sammael gives the rod to the shaido and tells them they can call it an "Oath Rod". This rod is exactly the same as the one the Aes Sedai use. I say this because he is smirking when he calls it an oath rod. He tells them how to use it to bind a person to them, i.e. making them say on oath while channeling. The rods are Binding Rods that were used for those channelers who need punishment. Reasons why the kin did not use their rod: 1. The mark of being binded is the ageless look which the kin do not have. 2. One of the forsaken says, Aes Sedai cut their lives short by binding themselves, the Kin are living longer then Aes Sedai, so are not binding themselves.