"Copying into the water" should be "blanching into the water", that is, putting washed and cut vegetables or raw meat in a strainer or colander, scalding them in boiling water and then taking them out.

The purpose of "blanching in the water":

First, it can remove pesticide residues and germs on vegetables, kill parasites and eggs attached to vegetable leaves, and ensure food hygiene.

second, it can remove blood and pollutants from raw meat.

thirdly, the green vegetables can be made into semi-finished products with ripe skin and raw inside, which can preserve the color and original flavor without destroying the nutritional value of the food.