I used Murphy's Oil Soap to clean my walls for the same reason. It worked well. Good Luck.
I can understand your problem with the awful odor of cigarette smoke. I would call your local fire department and ask them what you can do to rid your home of the smell. They should be able to assist you. I, too, wanted to purchase a house that I really liked but backed off because the cigarette smoke was just too strong and I could not breathe in the house. The owners were smokers for years and the odor was in the carpets, the fabrics, the walls, the floors, the wallpaper and even the wood. The odor was too extensive and so I passed on it. I wish you well and do try the fire department.
I have always just gone ahead and painted with a paint for non-porous surfaces (like Kilz). It seals in the toxins from the smoke and makes it much easier for those of us who are non-smokers, to breathe.
TSP or TriSodiumPhosphate is about the best thing on the market. And, if you rent, you can be compensated for your costs.
Vinegar in place of beach is safer and works better. Fill the bucket with a strong mix of the vinegar to hot water, then sponge the walls. You won't need to rinse or repeat (usually), and trust me the vinegar smell dissipates quickly, leaving the room smelling fresh but not vinegarry.
A shallow bowl filled with full strength vinegar will also remove unpleasant odours, as will wetting the end of a tea towel and waving it around-the waved tea towel works especially well in the kitchen when something has burned or smoked.
Our first home was a used trailer, and had the same problem! Even the inside of the fridge was covered in oily yellow cigarette film. I used the dollar stores brand of Murphy's Oil Soap, mixed up in a bucket of hot water, and used a sponge mop to wash the walls, ceilings, and floors, then left the windows open for a few days.
Add 1/2 cup of baking soda to a spray bottle. Top off with water. Shake well and spray the walls using the mist setting.
Add your voice to the conversation. Click here to answer this question.