To clean a toilet tank, take the lid off. Add a cleansing agent and wash the sides of the tank with a brush, watching out for the chain and other mechanical parts. Flush the toilet several times to rinse out all of the cleansing agent.
Typical flush toilets consist of bowls that hold water, along with plumbing that quickly empties and fills the bowl with water. Water exits the toilet through a hollow, u-shaped pipe that restricts the water height in the bowl.
The standard toilet design, known as the S-trap, was invented in the late 1700s by a Scottish watch maker. In the middle 1800s, the flush toilet came into wide use in London as the city's sewer system grew. Flush toilets were first used in wealthy homes in the United States in the late 1800s.