George Joseph Smith, the "Brides in the Bath" killer, got his sobriquet by his chosen method of murdering his wives: drowning them in the bath. It's believed the most likely way he did this without any evidence of a struggle was by grabbing their feet and sharply pulling so their heads went suddenly under water, and the shock of the sudden immersion caused them to lose consciousness, so he could try to Make It Look Like an Accident. The investigating police officer tested this theory with several experienced female divers of the same height and build as the victims, and the one who was subjected to the above action nearly went the same way - it took half an hour to revive her after he noticed she'd stopped moving.
Elizabeth Báthory, Hungarian form Báthory Erzsébet, (born August 7, 1560, Nyírbátor, Hungary—died August 21, 1614, Castle C̆achtice, C̆achtice, Hungary [now in Slovakia]), was a Hungarian countess who tortured and murdered hundreds of young women in the 16th and 17th centuries. She would bathe in the blood of her victims as a way to retain her legendary beauty and youth. It's a striking image and one that has endured to this day.
In the 1966 spaghetti western ‘The Good, the Bad and the Ugly’, a vengeful man, whom Tuco (The Ugly) had previously shot in the hand and permanently disabled, catches him naked in a bubblebath of all things. The man delivers a long speech about how he tracked Tuco down, and how he had lots of time to learn to shoot with his left hand... and then dies when Tuco shoots him with a gun hidden under the bathtub bubbles. So remember folks, ‘When you have to shoot, shoot, don't talk’.
Ever wonder why shower curtains stick to you? The Bernoulli principle says that as fluid speeds up, pressure drops. This creates an imbalance of air pressure: The air from the outside remains at the same pressure, pushing in on the lower-pressure air where you're showering, leading the shower curtain to have its way with you.