Purchased Airdog5 a year ago or more. It resolved the problem of skunk odors and fumes from nearby bus terminal. The last time I cleaned the metal collecting plate it started a static/hissing noise. Customer Rep told me to use "Awesome" cleaner which I got on Amazon, and gave it a third cleaning, which produced more black water. I dried and re-inserted the metal collecting plate and it still hissed/static noise but not as much, so I decided to just keep running the unit to see if the noise finally stopped. It did.
Periodically I remove the carbon filter and place it in our south facing window, as instructed by a Rep. - to "reactivate" it. I just recommended this company to a friend who lives in NYC, has a roommate who smokes.