Many experts will tell you that, in order to remove all the odor of smoke after a fire, you will have to remove the source of the odor. This means getting rid of the charred surfaces by either repairing or replacing them. Unfortunately, the problem isn’t that easy, as even in the case of a small fire, the smoke’s odor can literally get into the walls, so even removing everything, cleaning the entire room and using perfume or incense sticks will only mask the smell temporarily.
Some helpful tips are to use baking soda on soft surfaces and spray white vinegar onto hard surfaces like wood, in order to remove the odor naturally from those surfaces. Just remember never to use white vinegar on stone surfaces like granite countertops, as it will damage them.
Another good solution would be to wash and disinfect all interior walls. While this might do the trick in some cases, lingering particles of smoke could still remain to provide a mild odor.
To literally get rid of all the smell of smoke after a fire, an ozone generator might be needed. Renting an ozone generator might be a little costly, and it will cause some problems since it will require you and your household to temporarily evacuate your home while the generator is at work, but that’s practically the surest way to ensure that all the odor of smoke is completely gone.