Just turn it on to get rid of the bad scents. It's okay to keep the good smells.
When using any air purifier, make sure you know the difference between good smells and bad smells. Some you want to keep. Others? You want to be rid of as quickly as possible.
GOOD SMELL: Grandma's Lasagna
BAD SMELL: Uncle Dan's Possum Pastrami
GOOD SMELL: The leftover delivery pizza
BAD SMELL: that oatmeal you left on the counter last Monday
GOOD SMELL: the molasses cookies your neighbor brought you
BAD SMELL: the actual mole asses your neighbor tried to convince you were a hallmark of European cooking.
GOOD SMELL: the boiled shrimp
BAD SMELL: the shrimp with boils on it
GOOD SMELL: that fresh potato salad
BAD SMELL: the macaroni salad. Any macaroni salad. Ugh.