Still waiting for the clay I realized that I could use knives to cut the oranges.
I use the holder of a tealight for the blade of the knife.
For the handle I used 2 pieces of wood that's 0,1 cm. thick. I glued it with the blade between the two parts of wood. I sand it and painted them with acrylic paint Burnt Umber. Now I have some old knifes.