Yes, definitely try the deli cup in a dark spot. I would put him in the deli cup, leave him alone in it for half an hour to an hour, then heat up the pinkie super hot, put it in with him and then leave him completely alone. Check on him in half an hour. If he hasn't eaten, reheat the pinkie, put it back in with him and then leave him totally alone in his quiet dark spot for the night. If he hasn't eaten by morning, toss the pinkie out and try again in a few days.
As for the enclosure, you were right to ditch the pine. Aspen is fine for them. Besides your hides, I would also add some fake leaves from the dollar store to add ground cover. You can also use toilet paper tubes squashed a bit flat as extra hides. The more clutter and ground cover there is, the more secure he'll feel.