Spraying a persistent odour with fragrance air freshener will provide temporary relief, but will not solve the underlying problem. This is where activated carbon and/or zeolite can certainly assist, but which to use and where depends upon the nature of the smell.
If the source of the smell is localised and can be identified precisely, then placing bags of zeolite crystals as close as possible to the source of the smell will greatly assist in alleviating the problem.
If the smell is in an enclosed area such as a car, closet, wardrobe, cupboard, bathroom or toilet then 4mm activated carbon pellets either hung in a mesh container such as an old pair of tights or placed on a saucer or tray on a moistened piece of cloth or kitchen roll will provide long term relief up to six months. Again, bags of zeolite are also effective.
With a lingering smell in rooms or throughout the house, then the solution is more difficult. Under these circumstances, activated carbon works best when incorporated into a powered filter where the odour filled air can be drawn in and through the activated carbon and expelled as clean air. However, the price of this type of filter machine is quite high and would not be cost effective if it was thought that the smell was only transitory. The cheapest solution would be repeated spraying with a product such as Neutradol which is available from most supermarkets and which does have some odour destroying capabilities coupled with a number of zeolite bags concealed behind furniture and appliances.