Simmering granules hollyberry and mistletoe simmering granules are mostly used in oil burners, but are less messy as they don't need oil or water. just put a spoonful of granules in the burner and replace them when they're used up. simmering granules are a wonderfully versatile way to fragrance your home with your favourite aromas. aside from use in an oil burner you can also place the granules in sachets and organza bags in wardrobes and drawers for a gentle long lasting fragrance or place in dishes around the home for a constant pleasant aroma.