LOL! First I have to say, I loved your story. You certainly put a smile on my face.
As for Tess, She does think this is a fun game you are playing, and she is winning.
I am not sure how old she is, but
is it possible for you to watch her when she is in the house. If she is un-supervised this will make training her so much more
difficult.
That way you can catch her in the act, or before she even gets a chance to go into the kitty box.
If you can not watch her, you can even attach a leash to her/you so she has to be in what-ever room you are so you can watch her. I do not have a kitty, but when my dogs are pups they can be destructive, so
I had to make sure they were never in the house un-supervised as part of their training until they could be trusted.
Hope you had a video camera with you for
those special cute memories.