I’d say the next step is to show up there personally. Wait until nightfall then sneak out and leave a flaming bag of dog doody on someone’s porch and ring the doorbell. Some might say this is impossible since no one really lives there, but I feel certain you can do it.
Be prepared after that. McDonald Island is an Australian territory, so the Aussies may try to retaliate by TPing your house or something, those scamps