How to get rid of weird household smells...
First impressions last when selling a home, but one aspect that may make the strongest impression is one that has little to do with how the house looks.   A foul smell can hit a potential buyer before they even walk through the door, which can make it impossible to focus on the home's redeeming features.    So, addressing how a property "smells" is just as important as how it "looks."

1. Pets!   If you have pets, you are likely somewhat immune to their odors, However, future buyers certainly are not.   Pet odors can reduce the number of buyers that will be interested in a home.  Carpets harbor pet odors, and the smell of urine can linger long after an accident.  The first step to removing these odors is to vacuum the carpet, and then treat the urine stains with an enzyme cleaner.   If the smell remains after treatment, replacing seriously stained carpets may be the most effective solution, and can also enhance the home's value.

2.   Food!   You may consider yourself a master chef, but potential buyers don't want to breathe in the residue of your tasty culinary creations.  If you are living in the property while it's on the market, cooking outside on the BBQ whenever possible and holding off on cooking strong-smelling foods (such as fish, eggs, sauerkraut, or curry dishes), at least until your home is sold.   Cooking smells can remain in fabrics, so have curtains and carpets cleaned and consider removing any offensive-smelling furniture.

3.  Sewage!   A waft of sewer gas is enough to send anyone running, but it's not always a sign of a plumbing issue.   Often, the smell enters the home through infrequently used drains like the floor waste drain in a laundry room.  The pipes in these drains feature an s-bend, or trap, which is designed to retain water to create a barrier that prevents the sewer smells from coming in.  If a drain isn't used often, the water barrier can dry out allowing the smell to sneak in.   Regularly running water down all of your drains can help prevent such mishaps.

4.  Stinky Refrigerator!  To clean your refrigerator, turn it off and remove everything.  Throw out any old &/or expired items.  Remove the shelves and drawers and wash them in soapy water, and wipe the internal walls and surfaces down.  Using a vanilla-scented kitchen cleaner is a good idea.  Once the refrigerator is clean and restocked, use baking soda to absorb any remaining odors.  Your refrigerator also has a drip pan which can collect moisture and develop a musty mildew smell, so you should clean that regularly as well.

Whether it's just for yourself, or because you wish to sell your house, a clean good-smelling home is always a pleasure to visit (and will always be the first home to sell).    Candles and other scented "covers" can help, but they are temporary measures (that may backfire) and you will be better off addressing the source of the unpleasant smell.  This aspect is just as important, and sometimes more important, than the upgrades the property possesses.  Ask for an honest opinion from trusted friends or neighbors (and your Real Estate Agent) and do not take offense at what they tell you.