Is this the hognose? If so, you need to ask Chip what to do.
I _have_ heard of the water starvation method.
Here is a list of methods from Jenea Wood- who wrote a little Hognose book which I don't think is published any more. Guardian Reptiles.
In small container overnight.
Chicken broth.
Egg whites.
Frog scent.
Day gecko scent.
Put pink in small container with frog/day gecko for one day, then feed to the snake in the same container.
Split brain the pink.
Lure into feeding mode with a frog, then change to the pink.
Bait and switch- hold a frog or toad in one hand and the pink in the other. When he goes to bite, quickly replace with the mouse. Favorite method for adults.
Thaw pink in warm water. (Note- have you tried boiled? completely different).
Put pink in hollowed out cavity of a frog/day gecko.
Anole scent.
Rub entrails of frog/day gecko on the pink.
Tuna water scent.
Tease with a forceps.
Wrap pink in shed skin of Anole or day gecko.
I have two things to add myself.
Turtle food scenting.
And If you're worried, hoagies are super-easy to assist feed. I'd use a boiled pink, or peach fuzzy.
Hold the snake in one hand. Over a towel. With the other hand, press the nose of the pink against the snake''s mouth opening, and just wait. And wait, and wait, and wait. He should eventually open his mouth, then just ease it in. I fed a WC Eastern hoggy with this method, to adulthood, for nearly two years before she died of another cause. You'll get tired of maintaining a snake like this indefinitely, but it's easy and doesn't take much time once you and the snake get the hang of it.