The reason why you put dish soap in the bathtub at night is to dissolve and loosen grime which helps the bathtub become cleaner the next day.
Put dish soap in the bathtub and spread it over the inside of the tub and allow it to sit overnight
Then the next day turn the water on and scrub the bathtub clean and rinse the soap away.
As the water washes away the dissolved residue in the tub, take a squeegee and remove excess water from the surface.
Because dish soap is meant to break up oils and lift grease and grime from your flatware and utensils, there's no reason why it wouldn't work on the oily soap and human grease build-up accumulating in your tub or shower!
Dish soap is more for than just cleaning dishes as it also works on cleaning toilets, sinks tubs, showers and even your hands.
Dish soap can get rid of bacteria and even the viruses such as coronavirus.
Dish soap is mainly used to remove grease and food residue off from your dishes.
Like hand soap, dish soap does not kill bacteria, but it lifts them off surfaces to be washed away by water.