Yep first start with the deli cup over night, then if that don't work try live the same way.

One thing that gets them to take F/T at times is wash the pinks in a very mild solution of soap and water, Ivory is a favorite since it is so pure.

The theory is that frozen mice pee and poo on themselves, during their final sleep which is why they tend to stink.

By washing them you remove the pee/poo stink and leave only mouse smell, I mean you can't get rid of mouse smell on a mouse.

I have used this as a last resort on my hatchling house snakes and all but the most stubborn have fallen for it. Be it to get them to eat at all or to get them switched to F/T