As a natural solution to clean cigarette smoke off walls, use a spray bottle of warm white vinegar to remove stains and odors. The vinegar's warmth breaks through the layer of tar that causes the stains. Diluting ammonia in water and applying it to the wall is another simple method for removing stains.
A weak mixture of trisodium phosphate in water works on tough stains. It should be left on the wall briefly before it is rinsed clean.
If the room is wallpapered, a small amount of rubbing alcohol can help lift stains. However, rubbing alcohol should not be used on paint, as it may react badly.
If the stains are not severe, a mild detergent mixed with water may be enough to remove them.
Regardless of the product used, spray it onto the cloth rather than the wall. This minimizes wastage and reduces the chance of excess product running down the walls.
Once the stains are removed, the wall may require a fresh coat of paint. Stains should be removed even if repainting, as they can seep through a layer of paint. Clean the walls and use a stain-resistant primer to ensure the new paint looks its best.
If the smell of cigarettes lingers in the house, changing any HVAC system filters may be necessary. Ventilating the house can help, as can setting a square fan in a window to pull air out of the room. Further cleaning of carpets and drapes can also assist with odor removal.