I don't know if you saw my other post but my boy also went off feed recently and I ended up leaving a thawed rat in the tub with him after lights-out and he ate it within a couple of hours. I never thought he'd go for that but he did.
I'd try the overnight dead mouse buffet and see if he decides that F/T is ok with the right ambience
I tried that, too--twice! I ended up with a mildly smelly mouse in the morning in the tub, and not a fed snake, unfortunately.