2005 Chevy Cavalier Get rid of odors

My wife has health issues with smells. I or our sons smell nothing in the car. So I send her to a mechanic, he tells her to get this spray can of stuff. So I get this can of spray and spray it in the vent area at the base of the windshield. That has been over a year ago and she hasn't driven the car since. Now she smells the spray stuff. I have tried a number of things to try get the spray stuff odor out, but nothing has worked to her satisfaction. I haven't tried bleach. Any suggestions? I will send a donation should your suggestions work. I have another question I'll send at a later date and send a donation for both at that time. Thank you. John