You also need to change the cabin air filter behind the passenger glove box.
You can try an air cleaner fan with a HEPA filter, but I doubt it will work well.
The ozone generator is going to help dramatically, but beware of the health effects. Keep in mind that overuse of an ozone generator can degrade rubber, some fabrics, etc. So, use it a couple times for 20 minutes or so and let the car vent well. Don't keep using it if the results aren't satisfactory as you may end up with other longer term issues.
Good luck.