Nice but hard to clean

I find the kneader educationally valuable. Our 21 months old child likes to play with it and demands that we always him "Caster" tinker kneading rolls.
The Knetdosen contain only small portions, but this is sufficient at the age of our child.
The "Knetpresse" but falls also quite small and is difficult to clean, especially if the clay is still wet and very sticky.
It's annoying and leads pretty quickly to the fact that the colors mingle.
There unerem child but seems to be great fun, although a good evaluation.