I bought the OEM aldehyde filter from japan... it's expensive, but works way better than any of that charcoal crap you can find here... it removes not only odor, but pollutants from the air... you get what you pay, and it works... I've been using this type of filter in my protege for over 10 years now
https://www2.mazda.com/en/publicity/release/archive/1999/9904/990408ea.html
trivia: this filter design was women led R&D, according to a ford/mazda ad I saw years ago
both my mazdas are parked in the garage, and the 3 is daily driven... I usually use recirculated air mode, and finally replaced it this year when it reached 30k miles, but over 3 years old... it had some dirt/leaves in it, but nothing compared to the pic posted in this thread