I did that for my sesame street characters. I have a photo of it in my gallery. You have the right idea. After making your characters and letting them set, lay the stick on the back and cover with chocolate. It's not gonna look too pretty, so hopefully the back will not be exposed. Good luck!
You don't want it super thin where it will spread every where. You want it to be able flow through the tip but thick enough to stay put. Does that make sense? Always test on a piece of wax paper. If it's too runny let it cool down. If it's too thick, zap it in the microwave for a few sec. HTH!