To erase stains from nicotine on walls, use vinegar with water or bleach with water. If this doesn't work, you may need to repaint. The nicotine will stain your skin, too. If you're worried about cleaning up the vinegar or bleach once they've removed the nicotine, just mix equal parts of baking soda and water and spray the mixture on any leftover stained areas. This will clean up any remaining messes that might arise due to removing nicotine with alcohol or chemicals. The best way to ensure that you don't contaminate other areas of your house with nicotine is by using caution not to touch anything else in the room while it's being cleaned. Other areas of your home may also have residue from previous users, so be sure to test all surfaces before letting children play in or around affected rooms. You should also wear protective clothing when working with nicotine materials. Acid-based substances are toxic if ingested, so wear gloves and protective eyewear. Clothing contaminated with acid substances should be washed with soap and hot water after contact with the material. Acid-based substances can also cause skin irritation or damage if they come into contact with the skin, so take precautions not to let this happen.