Whenever dishes are washed, the Chinese tend to put the dish washing detergent on the sponge and then wash the dishes with the sponge, thereafter they will rinse the dish(es) in clean running water directly under the tap. It would appear that this is done not only in China but the whole of Asia as well. The Writer was raised to put the dish washing detergent in a tub of hot or warm water first and then to wash the dishes in that and then to rinse them in another separate tub of warm or cold water. It appears to the writer that if dishes are washed in the manner described as done by Asians, the supply of dish washing detergent will run out in no time and the dishes might still be oily and greasy. In addition, water is being wasted. Then again, this is just the opinion of the Writer.
Below is a video that was done by a laowai (foreign expat) showing you how it is done: