I don't keep Dumerils, but sometimes you just have to feed them what they want. I have a few BPs that decided later in life they only want live... so now they eat live. Honestly, I'd say let them eat live for a year or so and then work on transitioning over. Once they are a little larger, you have less to worry about going off feed. At that point in time, you can work on going with fresh killed, and then f/t heated to body temp.

It may just take longer overall. Scenting techniques and leaving the f/t mouse in the tank or a dark bag/box work for some but not all. Some stubborn feeders are just that... stubborn & you have to give them what they want.

Sorry I couldn't be more helpful, but I felt this response would be better than letting your question go without response.