How to Clean Walls with Flat Paint
Start at the top of the wall. Look for any obvious stains or streaks on the wall. Pick out an old pillow case, preferably white or a light color. Wrap this around the bottom end of a broom. Use a rubber band, or similar type tie to secure the pillow case to the broom. Start at the top of the wall, and in light strokes go over the entire wall. This will remove all of the dust and dirt, before you add any type of cleanser.
Next you will need a heavy duty cleanser. Look for cleansers that foam, and work on oil based stains. Any cleanser that sticks on the stain on the wall for just a moment will work. After spraying the stain, use a sponge or damp cloth to immediately wipe the stain off. Do not apply streaky glass cleanser type products, they will just leave a new runny stain on the wall.
A few minutes a day is all that you need to keep your walls clean. If you are cleaning up after children, look down on their level to see all of the stains. By squatting on your knees, or sitting in a chair you will be able to see the wall from a different view point. All hand prints, splats and spills will be more visible from this angle. Be sure to also check the doors. Stains seem to settle from hand prints around the door knobs and the inside flat section of the door. Moisturizer, or food stains that have oils in them that do not come out the first time, can also be treated with the Mr.Clean Magic eraser.
Cleaning your walls with flat paint regularly is the key to keeping them ready for company at all times. The maintenance on flat paint, is enough to drive someone with several small children up the wall. Try to avoid using flat paint in high traffic rooms. Rooms that are not good for flat paint are bathrooms, kitchens, and bedrooms of small children. If you are in a rental home, with white walls with flat paint, do not suffer from the landlord trying to save a few dollars. It may be worth it to repaint the walls in a matching tone with a durable paint that is formulated to be stain resistant.