Sure you can but it's not preferred in a Naked Pool.
If you do choose to use granular chlorine make certain you follow the exact instructions on the bag.
Granular chlorine must be put into a bucket of water to dilute before applying to affected areas of the pool.
Granular chlorine MUST be dissolved properly before adding to the pool water or you may risk staining or even turning pool your pool black.
DO NOT DUMP GRANULAR CHLORINE INTO THE POOL.