http://www.ehow.com/how_5656042_use-activated-charcoal-odor-neutralizers.html says that it can eliminate odors, but it only recommends it for small spaces.
When researching air purification you will come across a popular subject.
Ionisers VS Ozoninzer VS Activated Carbon
An air ionizer (or negative ion generator) is a device that uses high voltage to ionize (electrically charge) air molecules. Negative ions, or anions, are particles with one or more extra electrons.
This makes the air particles that get ionised turn into a 'magnet' because it is statically charges. You know like when your arm hairs rise to a piece of statically charged paper or sweater.
Advantages Is silent and can run anywhere in your home. Does not cause any health problems, it actaully good for people with allergies as it binds to dust and pollen. It will remove smells like cigarretes,smoke and other slight odours.
Disadvantages These particles don't evaporate into thin air.. once the ion binds to its victim it will drop to the floor, or stick to the wall.. in turn if you don't vacume(use a HEPA filter vacume) or clean your walls; overtime the odours can become worse and your hosue will suffer from static dust.
Ozone (O3) or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2). Ozone in the lower atmosphere is an air pollutant with harmful effects on the respiratory systems of animals and will burn sensitive plants
Ozone has this myth behind it that it kills bacteria and smells. In fact it is very dangerous for all living things.. In large quantities. As far as I know.. ozone has no benefit in any health methods.
Advantages Only industrial advantages.
Disadvantages When used in small rooms it can be lethal, causes lung damage and can kill other living things like plants
Activated carbon, also called activated charcoal, activated coal or carbo activatus, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.
Filters with activated carbon are usually used in compressed air and gas purification to remove oil vapors, odors, and other hydrocarbons from the air. The most common designs use a 1 stage or 2 stage filtration principle in which activated carbon is embedded inside the filter media. Activated charcoal filters are used to retain radioactive gases from a nuclear boiling water reactor turbine condenser. The air vacuumed from the condenser contains traces of radioactive gases. The large charcoal beds adsorb these gases and retains them while they rapidly decay to non-radioactive solid species. The solids are trapped in the charcoal particles, while the filtered air passes through.
Advantages It is highly porous and can adsorb gas,chemicals and liquids in various sequences and reactions. has no side effects.
Disadvantages It does stop absorbing once its saturated.. and could start to realease other harmfull gases if not replaced. You cant just put a carbon block in your room and expect it to adsorb air, it needs a pumping system or filtering system of some sort.
I hope that can answer your question a bit.
I would suggest finding the source of the smell and eradicating it with bleach/soap and/or other freshers/cleaners/chemicals. Then vent your room for 24hours.