Any piece of upholstered furniture heavily coated with soot should be cleaned by a professional service. If attempting to clean at home, vacuum the surface to remove spotty deposits of soot; then sponge with a turkish towel dipped in cleaning fluid. These and other solvents are very flammable. Work outdoors if possible or in well- ventilated rooms with open windows. Be absolutely sure there is no flame or spark anywhere in the area where it could ignite vapors from solvents no flame, pilot light, spark, no smoking. Discard cloths in tightly closed metal can, in trash. You don't want to start another fire!
Also avoid breathing vapors wile working. Read label on solvent and follow directions! The solvent will loosen oily soil so it can be wiped off with a dry cloth.
If the upholstery is washable, the next step is to "shampoo" the entire surface with "dry"suds made by beating a handful of dampened detergent to make thick lather with no extra moisture to soak into the fabric. Or use upholstery shampoo. Use this dense lather on a sponge or soft brush to lightly scrub one section, and scrape the soiled suds off with a spatula or knife. Repeat with clean suds, then wipe that section with a clean damp cloth. Continue shampooing and rinsing until all the upholstery is clean.
Wind a strip of clean cloth around a ruler, dip it into "dry" suds, and use it to wash between the seat and the arms or back of a chair or sofa. Wrap a clean damp cloth around the ruler to rinse those crevices the same way. Use only clean suds, clean water, and clean cloths. If a professional steam extraction service is hired to clean carpet, have them also clean upholstery and extract water.
For quick drying, open window, and turn on an electric fan. If windows are closed, turn on air conditioner if you have one, and also at same time use dehumidifier in the room with upholstered furniture to pull out the water.
Clean mattresses and foundations as for upholstery starting with dry cleaning solvent to reduce smoke odor but observe all the cautions and warning listed for use of these products. Before washing, let the solvent dry for a day or longer. Observe caution in using cleaning fluid. Read the label carefully and follow precautions suggested.