Cool find! I wonder if it would still work to some degree if a person rubbed on some red ocher mud under their camo clothing of choice? Wouldn't get direct sunlight, but still might be better than most commercial scent control.
Next time I get drawn for large game I want to experiment more with natural scent control as well as face/body paint. The .mil face paint sticks make me nauseous, give me a headache, and the commercial stuff smells just enough better to not quite turn my stomach.