Because the God of Stove left the house on the 24th of 12th lunar month, people start to clean the entire house on the next day, the 25th of 12th lunar month. To cleaning house is to dust every corner, clean all windows, wash all rooms. That's lots of chores and children need to share some works. The red Chinese folk art paper cuttings will be pasted on windows on this day. Then they will plan how to do the house decoration for the coming new year.
Before Tang dynasty, cleaning house was a religion ceremony to get rid of disease. Yearend cleaning house was popular during Tang dynasty. The yearend clean day was set on 24th lunar day of 12th lunar month in Sung dynasty. Today, depending on geographic area, some people start the dusting job right after The God of Stove leaving the house on 24th. And some people move the Clean Day on 26th of 12th lunar month.
One folk song sings, "23rd day to farewell the God of Stove, 24th day to clean the house, 25th day to make tofu, 26th day to kill pig, 27th day to kill chicken, 28th day to make rice cake, 29th day to fry fat meat to preserve lard, 30th day to wait for new year". That tells some people choose the Farewell Day and Clean Day differently.