We've seen that inanimate objects can be made to 'eat' a Demon Fruit; can this process be used on a Sea-stone object?
While a clear answer to that question hasn't been given yet, it is most likely impossible. Sea stone nullifies Devil Fruit powers to begin with, so even if it were possible to feed a sea stone object a Devil Fruit in the first place, the stone's effects would nullify the fruit's powers, rendering it useless.
We are still not sure about that. But I believe that a sea-stone cannot eat a demon fruit. It will just nullify the fruit or maybe destroy it.