I can answer that.

The reason the dog runs around the house for 20 minutes is to get dry. Specifically the ears. When wet, you'll notice that dogs (most breeds) can "pinch" their ears shut. A dog's main priority when wet is to NOT allow water in their ears. That is why, I'll guess, when she runs around she will often rub the side of her head (ears) on anything soft (or sometimes, if a "less smart" dog, hard) they can find -- carpet, etc.

So now you know.

Just like how they can shake themselves dry 100 times better in 2 seconds than you can do with a towel for 5 minutes!

Amazing -- and exactly why my dog wouldn't step foot in that box.

:-)