Yes, Indias Devli Green Slate can be used for exterior applications in very dusty climates. This type of slate is known for its durability and resistance to weathering, making it suitable for outdoor use. Additionally, the natural color and texture of the slate can help camouflage dust and dirt, making it easier to maintain in dusty environments. It is always recommended to follow proper installation and maintenance guidelines provided by the manufacturer to ensure the longevity and performance of the slate in any climate or condition.