Got my Practise Head!!

I finally got my practise head but I am a little disappointed. The idea is cool, however it doesnt clean up as it sais it would. I did everything I am supposed to do and more and I still have stains in it, starting after the first face and just getting worse with each additional face I painted. I am going to email the company about it.

Here a few faces that I did that are easy and I know I can do quickly. What do you think?