AC SMELL- can it be avoided?

[dvl57]

I know from past vehicles that one needs to cycle the ac blower w/o the AC running to cycle out the cool air, but is that necessary for Hummers?

On my brother's BMW M5, he has to blow out all the cold air prior to shutting off his car or else have a moldy odor come out of his air vents. My previous truck- my Land Rover, I didn't have to do this. On my H2, I noticed the moldy odor so I bought some PURE AIR and shot it through the air intake as well as my vents. It eliminated the odor; however, do we need to cycle the cold air out before shutting off the truck?

It's kind of a hassle and somewhat unheard of. Then again, I live in Houston, Texas where it's really hot and humid...especially during these summer days.

Some advice would be appreciated.