First Oud burnable and I must say that I choose wisely. The importance of type of charcoal used cannot be understated. Stay away from the common type you may find readily available. I also use a mica plate with great results after a friend's recommendation. Hints of pepper, leather, and tobacco linger well after the burn has completed.
I've been looking for some good Hindi chips for fumigating and these are it. Quality and a great price! Definitely recommended.