I've always loved duck with orange so I'd let it sit overnight in orange juice spiked with a little 5 spice. the next day id pad it dry and leave it to air dry in the fridge for at least 2 hours before stuffing the cavity with an orange cut into quarters. A little salt and pepper then onto the smoker for a low and slow cook. Towards the end of the cook throw a piping hot chimney of coals in to get that skin crispy. Maybe a brushing of orange marmalade for the last few minutes. Best of luck with your cook. I look forward to seeing what you do with it.