I requeened my Cordovan split with a Russian and they rejected her. Followed Dwight Porter's instructions to the letter. 24 hours queenless, 4 days with the cap on, 2 days with the candy, and it looked like all was well. I found her released & walking around. One week later, no queen, just a bunch of started queen cells on the bottom of the frame I had found her on (swarm position).
Don't know if they killed her or she took off, but she's not there. Finally tore down the hive this past Thursday (July 1), and no sign of her or any more brood.