How can I clean smoker walls (I can't use TSP in my country)

My mother chainsmoked like crazy for years in her room and living room, I managed to clean the windows and some parts of those rooms with an amazing result honestly, but I have no idea how to clean the walls, they have that characteristic yellowish color that a smoker wall have, and also stains because of the smoke, for clarification, the walls are normal walls painted with plastic paint.

I read here that tsp works perfectly, but I can't find it in my country and ordering from the US it's expensive and I can't afford it, any other recommendations?