I came across this excellent article about the odours in ones home when trying to sell. I've shown many houses that instantly put off my buyers the second they entered the home and were greeted by an unpleasant odour. 

Most people think they keep a fairly clean home. I know myself I feel my home is relatively clean. But whenever I steam clean my carpets, it's amazing to see what gets drawn out of them. No matter how many times you clean your carpets you will find you can extract a fair amount of what seems like an endless amount of dust and dirt.

With that in mind you can imagine what odours can be hard to get out of your home. Odours can set in to not only the carpeting and draperies, but even the walls, cupboards and vents. Even the nicest of homes can offend people if their first impression is hindered by unpleasant odours.

That is why it is important to hire a professional that will help you in preparing your home for sale. It is our job to let you know what our first impression is and help you to make any changes that might be necessary. Sometimes all it takes is to have your carpets cleaned and walls painted. Other times you may need to hire professionals to come in and shock the air quality within the home. Worse case scenario, you may have to do all of the above and perhaps remove any carpeting or draperies in order to eliminate the unpleasant odour. When you are looking at selling your biggest asset a few thousand dollars spent may mean saving you the loss of tens of thousands when negotiating with interested buyers. The last thing you would want is to have to knock the price of your home down because of something you could have avoided, or worse yet have people walk away uninterested from the home because they cannot see past the smell!

http://www.househunting.ca/vancouversun/Buying-Homes/Sweet+scent+successful+home+sale/4121180/story.html