You got conditioner on the base. Next time ONLY aply conditioner to the hair itself. Pin the hair onto the styro head and work the conditioner through the hair, let it sit for a few minutes, then rinse it out.

As for what you have now, I would wash the base with dish soap first, let it dry, then wipe it with alcohol. Might have to do this a couple of times. You have to get the conditioning agents off of the base, mainly the silicones (which are in most conditioners).