See, according to me, i feel that a napthalene ball goes through sublimation, and so does it's form of gas. Since it's point of sublimation is at room temperature, it gets sublimated and thus changes it's form from solid to gaseous state. Eg: solid Carbon-di-oxide or dry ice, when kept under high pressure, changes it's state from solid to gas, when pressure is brought down to 1atm.
However, the thing of an incense stick is not very sure because, all incense sticks do not sublime. If you go to any site you might find the description given for the incense stick given as sublime or not sublime. So, I am not very sure.
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