Coco chips/coir isn't perishable in the sense that as long as it's not stored wet where mold can grow, and stored so it's dry in a closed container (to keep it from airborne spores etc.) it will last until you use it. But it's not really reusable like
grow rocks are. You can try to clean and sanitize it for reuse, but it will be extremely difficult to separate the root mass from the coco coir/chips. The organic mater (roots, leaves) that were missed can feed pathogens, and/or disease to your new plants. So I simply don't even try to reuse it, I just stick it on the compost pile after I use it.
The coco coir/chips do slowly decompose, but you wont need to replace it while the plants are growing, unless maybe your growing some real long term plants like trees that you grow for years. Then you'll probably want to transplant them into some new coco chips/coir after 2-3 years, but I don't know if that would be needed for sure.