Let's see if I attach the photos correctly!!!
The interior looks a lot like a rice cooker, but the pan can not be removed. There is a small hole at the bottom where water flows through and then up the exterior tube that give you a visual water level. This is the part that confuses me as far as hot chocolate is concerned, if the tube is filled with a chocolate mixture, how do you clean it. There is just no physical way.
Maybe Clay knows something about this and has used the Zojirushi???
Hope these photos help....
Interesting thought. I wonder how much like a hot water kettle it is--being that if there is a raw heating element in it the amount of output is sure to scorch at the source, and clean up would be a beast. I need to see if there is anyone selling these local to go look at one.
Your idea is solid though, just keep the liquid at temp and then drop a few pre-weighed ganache bits in and you're good to go.