Recently I learned a very useful tool in Audition; the Noise Reduction Process. This came in very handy when editing a podcast and there's a lot of bad white noise in the background. Well, this effect saves the day! If I select a piece of white noise from an episode (it has to be only white noise by itself) then right-click it and click "Capture Noise Print", then select the whole episode (or wherever you want it to take out the white noise), then go to the "Effects" rack, then select Noise Reduction/Restoration > Noise Reduction (process), it'll lead me to the control panel where I take it out.
It should look like this:
The waves in the panel might be bigger or smaller for yours (depending on how loud the white noise is). You might notice that I put the noise reduction strength at 100% and 100 dB (Decibels). I think that's the best way because it gets as much as possible out. Now, it doesn't get all the white noise out; only when the guest or host is not speaking. But it does slowly go down when they're done talking; so that it doesn't sound like it was cut out.
I hope this helped you (if you use Au) in not just podcast editing, but any audio.