Combine the juices, honey, cloves, cinnamon sticks, ginger, lemons and oranges in the slow cooker.
Cook on low 6 to 8 hours or on high 3 to 4 hours. The longer it cooks, the more the flavor from the spices will permeate the wassail.
If desired, remove the cinnamon, citrus slices, cloves and ginger with a slotted spoon before serving. Float the cranberries in the tops of the glasses for garnish and serve warm.