I always thoroughly wash any rice before cooking. Just because we don’t know what it’s been coated with. I love the idea of dehydrating cooked rice! I usually Food Save my leftover rice & freeze but I’m looking into non-refrigeration methods of keeping easy foods.
I don't dehydrate cooked rice for myself just to go with dog food as it easy to soak in broth in the morning then it is ready for his evening meal. Also when I make rice for us I normally make more than we need that way we can have it over two days as well as the dog can have it.