I have used local honey and or cane syrup. Use paper towels to dry the pork and then apply the sweet stuff, then your rub. I kept the smoker at 225° and the pork developed a nice crust as it would with brown sugar. I have always had a water pan in use when smoking the butts. Honey has a similar profile to the brown sugar, maybe a bit lighter and the cane syrup defintely has a bolder, deeper flavor.