It can act a insecticide if it is not too much and is well diluted in water. If it is too concentrated, it can actually kill the plant. Kitchen/Dish detergent is milder and less damaging to the plants than laundry or dish washing detergent.
- I would think the detergents in the soap would kill the cells in the plant and therefore the plants would probably die.
More soap will kill the plants and less will take about a day