The Aqua Eyes/Lip pencil? MUFE sharpener works great, or Urban Decay's grindhouse sharpener. If you're talking about a different type of pencil, I apologize.
I've had friends with the Aqua Eyes pencil, and they thought it was plastic, and didn't think it could be sharpened. The black part is wood (or a wood type material), and can be sharpened easily.
Hope that helps!