My 9yo dd has some of these (well, we share them) and they work really well if you put them in damp hair with a bit off product and either leave it to try or blow dry it with them in (then let them cool before removing)
DD has requested 'hair curlers' on her wishlist for 11th b'day. I think she's a bit young for tongs or heated rollers, although I might consider them - any other suggestions please?
She has thick quite shiny shoulder length hair with a slight wave. So far she has just been experimenting with plaiting bits when wet. I don't know exactly what she has in mind, probably something completely unattainable, such as a full transformation into Cheryl Cole.