I lucked out and found a refurbished "hand-crank" pencil sharpener online. This means Derwent Drawing pencils are back in play! It takes some serious hardware to sharpen those bastards, but it's worth it.
I noticed with these tools, the line they create is REALLY dark. Without consistent attention to line weight, a pose can be ruined pretty easily. Eventually I learned to scribble a bit in the corner of the page, breaking in the pencil tip before each pose.