I myself have not had to starve my dats. My little ones get a daily feeding of pellets and bloodworms/and or shrimp. The few dats that I have that don't eat pellets eat the shrimp and bloodworms. And I do it in that order.
If you have experienced your dats rushing to the front of the aquarium that is the best time to throw in what you want them to eat. If they don't lay off feeding them for a few more hours and try again.
Usually a 36 hour time frame inbetween feedings should do the trick to get a few to grab ahold of some pellets, or in this case something else. I'd suggest shrimp though, just seems like it would be more appealing to feeder eating dats, not that I would know though
Try mixing live foods with frozen ones. Put the frozen bloodworms and live worms in a cup with a little bit of tank water and let it thaw together. Then pour them both in a little bit at a time. They should at least try to take a bite of the frozen stuff and you'll trick a few of them into eating the frozen worms.