My Rottie, Annabelle, was the worst. If I was in the shower, she would at least have her head in (many a times she'd jump in and stand there staring at me).
And oh, the magical awe-inspiring toilet flush. Poor Belle. She was completely confuzzled and mystified watching the water swirl down and away and then refill. Her head would cock to one side, and then to the other, and back again.
The only dog I've owned that had no desire to follow me into the bathroom was Wrigley, my Shar Pei/Cane Corso mix. If it wasn't something HE wanted to do, it didn't get done. He was too independent to stoop down to the level of following a human to a tiny room where baths occurred.
The Hokey Pokey. That's what it's all about.