Percocet used for pain relief is a narcotic medication and prescriptions can prevent people from getting high on Percocet without medical reason.In fact, the Percocet high feeling can get you into lots of problems.
I think the formula of the perfume itself decides how fast it will spoil. My perfumes from Britney Spears Curious and Salvatore Ferragamo went bad within a year and a half. The Britney Spears one developed some precipitation and started smelling like alcohol, while the Salvatore Ferragamo just smelled plain weird.
This way you will be sure that your breath smells fine. If you are having dreams about bad breath another possible interpretation of this is that you actually do have bad breath. This can be hard to grapple with, but it is not impossible, just make sure to brush your teeth and use mouthwash right before you go to bed.