When you put the snake in a deli cup is there aspen in it for the snake to burrow? I have found that even snakes that will not eat in an empty deli cup with a pink will take food if they have substrate to burrow in. What I have done in the past is put the snake in a deli cup that has enough aspen in it for the snake to completely burrow. After letting the snake settle in for a bit I put 3-5 live pinks in the cup on top of the aspen and leave the cup overnight at the cool end of the shoe box. Whenever I have tried this the snake has usually eaten at least one (but often times more than one) of the pinks by morning. After once or twice like that they are usually off an running.

Rob