Gail and Diana need to take a lesson from the Doctor Who and track down the novel Alien Bodies by Lawrence "Mad Larry" Miles wherein the Doctor discovers his future corpse has been weaponised. Once he gets his hand on it, he literally nukes it because he recognises not only the massive danger it presents but also that it's his body and it's been violated.
So here Genocide is Diana's body ripped out of time and massively supernaturally and superscientifically violated to become a god-level weapon of destruction and spiritual desolation. That is not something you casually dispose of in the depths of the ocean, home to any number of Aquaman's mystically empowered foes and where it might have hideous environmental consequences. No, you rip your lasso out of it then hurl the shattered body as hard and as fast as possible into the heart of the sun (or get your friends in the Watchtower to do it for you.
And then you go and rip Ares' balls off and feed them to him.