It turns out that the real solution may be to drop the heated plastic altogether in favor of using photopolymer "ink" that is solidified using UV light! It's safer for young children, the very population for which I envisioned using a 3D pen. And, I THINK that clogging will be a thing of the past.
Right now the best information about the CreoPop can be found on their Indiegogo site.
What I will do here is to post some very cool videos showing the CreoPop in action. First, we have the obligatory sales pitch found on their indiegogo page.
Now, you HAVE to admit these guys are ingenious. While no 3D pen is going to make any of us world renown sculptors, they do have a place in teaching 3D printing concepts.
Here's a quick review that is excellent at demonstrating the challenges as well as the unique aspects of the cool ink process.
The materials themselves are interesting. Changing colors seems to be simple and specialty inks are promised. Here is a sample that creates a deer using two ink colors.
Whether or not you see a 3D pen in your future, I think it's worth while to check out their Indiegogo page as an example that demonstrates that there is still a LOT room for innovation in the 3D realization space.
Link to CreoPop Indiegogo Page