Even if you paint in glycero, I advise you, leaching is more than recommended.
To do: Cut the meter. Take natural sponges in a paint store ( no synthetics that do not rinse). Take a bucket of water and lye St Marc (several boxes). If it is very dirty, you wet the sponge and pour the detergent directly onto the sponge, then spreading it on the wall. Qq minutes after you rinse from the bottom. If it's less dirty, especially less fat, you put the detergent in water, a box for a bucket. Wear gloves and goggles and old clothes. Rinse otherwise the new paint will not :-)
Hello If you have any places you can MAINTENANCE OR CLEANING very bold with the product takes off wallpaper pure or diluted in Hot water is very effective it dissolved fats act as you leave for tapestry and you wash your st marc you save time and energy Good luck