Use a leather cleaning product that is pH-balanced to work with leather goods. This ensures that it doesn't have a negative interaction with leather.
Apply a small amount of the cleaner to an inconspicuous part of the leather item to ensure it doesn't damage the finish. Some leather cleaners are incompatible with suede and very soft leathers.
Wet a dry cloth, and place a small amount of leather cleaner on it.
Rub the cloth against the affected part of the leather until a light lather forms. Continue rubbing in a circular motion until the dried hairspray loosens and dissolves.
Wipe away the lather with a wet cloth.
Drag a dry towel across the surface of the leather.
Apply a leather conditioner to the leather item to rehydrate and extend the life of the material.