Walkthrough
After exploring all Five Island has to offer without finding the second password to unlock the Team Rocket Warehouse, it will be time to head to Six Island next. Six Island contains many different areas, including the Water Path (east of main area), Green Path (north of Water Path), Pattern Bush (located within the Green Path), Outcast Island (north of Green Path), Altering Cave (found within Outcast Island area), Ruin Valley (south of Water Path), and the Dotted Hole (found within Ruin Valley). You will even find your Rival within the Six Island Pokemon Center, but, again, he will not challenge you to a battle.
Items
Leppa Berry: ItemFinder
Poke Mart Items
Ultra Balls, Full Restore, Max Potion, Revive
Full Heal, Escape Rope, Max Repel, Dream Mail