I don' t know if scent sprays have a shelf life or not....I would suspect that they do. Forget the store-bought stuff, though.....make yourself up a batch of this very effective, very cost-effective home-made scent-killer each year. Then you won' t be so broken-hearted when you throw it away in January, and make a new batch in September:
 Peroxide 3% <br />
16 oz. (2 cups) Distilled Water <br />
1/4 cup baking soda <br />
1 oz. unscented shampoo (I use Cabelas hunting shampoo) <br />
Mix in a large bowl (don' t shake up in milk jug) so the baking soda dissolves)and pour into jug. <br />
Let sit for several days, so the chemical reaction settles down, and don' t leave in a tightly sealed container! I use a gallon milk jug with a snap on cap. You can use the above amounts in proportion for a gallon, you do the math, lol. I have several used sprayers and fill them from the gallon</i> )
I can' t recall who posted the recipe (a couple of years ago, I think), but it seems to work great! My wife can' t ever seem to catch me leaving the house now!
Good luck!