It can't (well, shouldn't) be just melted chocolate, it needs to be properly tempered in order to hold its shape and maintain the shine -- otherwise it will bloom and be streaked or cloudy.
You're basically right about forming the curl, though. It's spread onto sheets of acetate which are then combed or scored to create the desired width, then the acetate is twisted so the chocolate is on the inner side and they're secured until cooled and hardened.
Don't worry I use tempered chocolate whenever I make chocolate for decorative purposes, but go the lazy normal melting route if the chocolate needs to be inside in anyway. Also the chocolate spirals were sooo easy to make in the end. I didn't really have anything that could hold the spirals, so I thought I would just use a regular glass to hold them, but in the end after letting the chocolate cool down a little they were able to hold themselves after being shaped into spirals!
Here's the result! (sorry for the amount of pics...)
Charlotte Mousse Cake
Composition: Ladyfingers forming the charlotte fence. From the bottom a soft sponge cake, then blackberry mousse, pistachio cream, orange mousse(with candied orange zests and chocolate chips) and whipped cream. Decorated with chocolate figures and more orange zests.
Great cake, if a bit too heavy on your stomach(there's cream in pretty much all things). But I really like the look, it came out exactly as I had envisioned. The orange mousse was really good, I had reduced the water from the juice from 3 oranges, so the taste was really sharp, only to be supplemented by the candied zests, and made even greater with a chocolate chips combo. The only thing that went 'wrong', was that I had forgotten to brush the inside of the ladyfingers with syrup, which resulted in the orange mousse to leak out and soften the bottom part of the ladyfingers. I could have let the mousse become more firm before pouring it on, but I didn't have the patience.
Bonus work in progress pictures! I try to keep the mess to a minimum whenever I work in the kitchen, constantly working on cake->washing the dishes. Still a mess everytime XD
Everything is ready for the orange mousse
My dog Shikko eyeing the cake as my gf eats a piece.
'But I'm really really hungry!'