Here's a team you can use:
Whimsicott with Prankster (No item) - Acrobatics, Memento, Knock Off, Taunt
Durant with Traunt (No item or Leftovers or Choice Scarf) Entrainment, Iron Head, Thunder Fang, X-Scissor
Dragonite with Multiscale (Dragon Fang) Dragon Claw, Roost, Protect, Dragon Dance
Make sure they all have perfect EV's for each of them, you need a lot of speed for the PWT.
Here's what the team should do:
Start off with Whimsicott, try and score a Knock Off or a Taunt before using Memento, you'll faint so switch to Durant, use Entrainment and the foe will gain the Traunt ability, now switch to Dragonite. Protect on every turn that Truant isn't activated and Dragon Dance on every turn Traunt IS activated, after you get a few Dragon Dances up... well, sweep until your hearts content.
That's how I got through the PWT, although steel types are a bother if they catch you out, especially Jasmine's Steelix with Iron Defense or Bulk up.
Other than that, this team is unbeatable to NPC's unless they catch you off-guard somehow.