I have "fire-cured" leaf that is newly yellowed, as well as leaf that had completed color-curing. I did this in a steel trash can (in which large holes had been drilled into the bottom) sitting on top of a Brinkman smoker.
The smoker was fired-up 1 to 3 times a day, daily, for periods ranging from 7 days to 30 days. The bottom tray of the smoker contained a small amount of charcoal onto which one or more aluminum foil packets of wet wood chips were directly placed. The foil packets were punctured with a fork. I kept a large pot of water on a rack between the coals (at the bottom) and the leaf (in the can atop the smoker).
Since the entire apparatus was outdoors, and cooled overnight, the leaf was in medium to high case each morning (this was done during the autumn). The more days that the leaf is fired, the darker the tobacco becomes. Even the short (7 day) firing imparts a lasting, smoky aroma. I have used wood chips of apple (very nice), oak, maple and hickory.
Other than the holes in the can bottom, the construction (thermometer, hanging hardware) is identical to my Cozy Can flue-curing chamber.
Bob