Given the following smelting recipes:
Gold ingot -> furnace (0% experience chance)
Dirt -> crafting table (100% experience chance)
And arranging them in a furnace like so, such that the 0%-experience item has been previously smelted while placing the 100%-experience item in the queue:
Taking the 0%-experience items out of the furnace will provide the player with experience, using the chances from the item in the queue.
A secondary issue is that arises due to this is that if no item is in the cooking slot, no experience will be provided when taking out the cooked items.