Preheat smoker to 250°F.
Drain beans and place in a 12-inch square disposable aluminum foil pan. Sprinkle garlic salt over beans. Cut butter in half and push the halves down into the beans.
Sprinkle brown sugar over beans and cover with bacon slices. (To be less sweet, cut back on sugar by ½ cup.)
Cover with aluminum foil and place on the second rack of smoker and smoke for 1 ½ hours. Remove aluminum foil and smoke for an additional 30 minutes. Remove from smoker and discard bacon. Stir beans well before serving.