Oogy's suggestion was a good one--I quickly learned that the alpaca fiber needed to be carded. I know that some spinners could work with the combed-only fibers, but I need fiber that is more uniformly fluffed up (I'm sure there's a real term for that!).
I've done an experiment to see how the spinning might go. This is about 20 g of singles.
I plied it and made two little skeins.
Then I washed one in baby clothes detergent. This proved entirely insufficient. The yarn smelled worse than before it was washed, and it was still rather dirty. A second wash in Dawn dish liquid made a big difference.
Next step, once the washed skein is dry, is to knit a swatch!