Window screens trap dust and dirt over time, becoming unsightly and inhibiting airflow through the window. While it's easier to remove the screens before cleaning them, you can leave them in place if it works better for you. Clean the window screens from either the inside or the outside of the house first. They may be clean enough after you finish one side. If, however, they still look dirty, clean the other side as well.
Dust the window screens. Use a dry rag first to knock off the loose dust. Then go over the window screen with a soft brush vacuum cleaner attachment to remove more set in dust and dirt.
Lay down some old towels or plastic sheets around the windows and floors. Cleaning window screens while they are still in place can become a messy job.
Fill a bucket with warm water. Add a few squirts of dish soap to the water. If the screens are really dirty and need to be deep cleaned, mix 4 tbsp. of dish soap, ¼ cup of ammonia, 3 tbsp. Borax powder and five gallons of water to make a cleaning solution. Fill another bucket with plain warm water.
Dip a rag in the cleaning solution and wring it out well. Use a lint-free rag such as an old t-shirt or cotton cloth so that lint does not get trapped in the holes.
Wipe down the window screen with the rag and cleaning solution. Rinse and wring out the rag frequently to remove dirt and dust from the rag.
Dip a clean rag into the bucket of plain water and wring it out well. Wipe down the window screen several times to remove the cleaning solution residue and any leftover dirt and dust. Again, rinse the rag out frequently. Allow the window screens to air dry.