I dont care if mine played with the tree either, its actually cute, but mine would eat it and vomit, so mine had to come down.
There was an article going around with a lady that had her tree so beautifully decorated (with 2 cats) and every day, she would document with pics her Christmas tree. By the time Christmas had arrived, the tree was terrible, the cats were all in it, it was a mess and it was hilarious
She didnt stress, she just let what happen, happen and everyone, including the cats had a great time. Its just a tree. If you have plastic things on it and there is nothing that can hurt him, just relax and enjoy it.
On a different note, please dont spray your cat with water. So many people out there think its ok, but its not. A cat's ear is very sensitive and if any water gets into his ears, he can really develop a serious infection.
If you are going to lock your cat up and cause him undo stress, which it will, why not just take the tree down? That doesnt make sense that you are willing to stress your cat, which will in turn cause him health problems and cause you stress, over a tree, just take it down and let everyone enjoy Christmas.