Short answer: no legitimate method exists. The Wii version of Call of Duty: World at War follows the series' established progression system—weapons, attachments, and perks unlock as you earn experience points through gameplay.
Instead of searching for shortcuts, focus on efficient XP earning:
The grind exists for a reason: it teaches fundamentals that make later unlocks feel earned. Embrace the journey from rookie to veteran—it's the core Call of Duty experience.