I was doing some research on removing stale smoke smell from interiors and there are a lot of recommendations for einszett Klima cleaner which cleans the a/c system at it's core. My only conern is it requires spraying a foam directly into the evaporator core. Most reviews say to insert the included hose straight down the center vents and then it will reach the core. Wait 30 minutes, and then turn the AC on full blast. Does anyone know if the center vent on a CX9 would be the proper place to insert the product to reach the evaporator core?