Just a suggestion.
Next feed time offer a smallish mouse then right after throw a rat about the same size at him,sometimes when they get into feeding mode they will eat anything.You have probably been told about all the other tricks as well such as washing the rat then rubbing a mouse all over it etc.Be patient,the main thing is at least the snake is eating which is a whole lot less stressful than having one that wont.
cheers M......