Cleaning Smoke Yellow Walls
If you have had a vacancy that left a yellow film on the walls from a two-pack a day smoker, do not treat the job lightly. First of all, do not paint over smoke-yellowed walls. That traps the smoke in the apartment or house for the next decade. Once the paint dries, it will become more porous; and the odor will slowly leach out over time.
The solution is to neutralize the walls. This can be done by a crew of workers who scrub the walls. That is quite expensive. H Factor can be applied to the walls with a foaming sprayer. Then, agitate with a bristle brush. H Factor is very effective an breaking up the smoke film and neutralizes the many aromatic chemicals found in smoke.
The process will not restore the color to its original look, but you can now paint over the walls without concern for a latent odor.
Foaming spray with H Factor is most effective because the product clings to the wall allowing plenty of time for the product to do its work. Agitate the wall with a bristle brush, and use a sponge mop to collect the residue that is rinse in a pail of water. This is not easy work, but it is as easy as it gets. The alternative is a lot of hard scrubbing instead of wiping the wall with a sponge mop.
If the carpet can be recovered, you can put the H Factor in a 1:9 mi with water to extract the carpet. This get the solution down into the fiber and backing.
Use the electrostatic sprayer to treat everything. Treat drapes, furniture, closets, cabinets, cabinets. You can follow with a wipe up if you like. The odor is already cancelled, but the film needs to be wiped away after the treatment.