They should be eating ever day, prolly twice a day. FWIU they fully digest every 6 hours, so every 6 hours they can eat.
I never had much luck teaching them to take frozen krill, I think because there is so much damage to the krill body that it doesn't look like food to the cuttle anymore. Did you try drawing eye spots on the krill? Are you able to get any live shrimp or crab for your local aquarium store? I also think they just don't like krill all that much.
If you have been chasing the cuttle with the food stick, I would be he is moving away from it because he is scared of it. Not much you can do about that.
You could drop the krill into the water and see if the cuttle strikes. Thaw about 10 pieces before you start. If he doesn't leave the krill and try again. Keep trying. If he still doesn't strike, leave the krill for a while and take it out as gently as possible. You could also try tying some thread to krill and hanging it in a high flow area to see if the cuttle will go for it.
This guy is wild caught right? They can be problematic in terms of eating. If the tank is in a high traffic room, consider moving it, or at least covering it for a few days to give him a 'feeling' of security.
Again, your best bet is some live shrimp or crab. Without that, I am worried any attempt at weaning won't work.