Properly destroy ItemModProjectile

How to destroy an ItemModProjectile? Looking to destroy arrows after 5 seconds, for example:

Code:

        private void OnWeaponFired(BaseProjectile projectile, BasePlayer player, ItemModProjectile mod, ProtoBuf.ProjectileShoot projectiles)
        {
            if (mod.name.Contains("arrow")) {
                timer.In(5f, () => {
                    mod?.KillMessage();
                });               
            }
        }