Buyers can be put off by odours emitted by pets, food, mildew and dirty carpets. This is why it's important to ensure your home is properly cleaned - especially in areas where odours originate. Fresh air is a simple and easy way to reduce odours, so ensure your doors and windows are open on the open home day. There are also several products on the market that can assist with eliminating odours. Note: I'd advise staying away from strong scented candles.