All you need is a bottle of cheap coconut conditioner, and some cornflour.
Put about five tablespoons of conditioner into a bowl. Gradually add cornflour a spoon at a time (the recipe uses a US cup of cornflour, but we found it better to add a bit at a time and if it gets too dry, add a tiny bit more conditioner). The mixture looks slightly dry at the perfect point, but use your hands to knead it into perfectly soft and fragrant dough. If it's too sticky, add more cornflour.
We added a few drops of food colouring once it was made, and the children watched it ripple into the dough as they played with it.