I think Russ said throw away a moldy _humidifier_, not a moldy _humidor_.
If a humidor gets mold in it, let the humidor dry out. The mold will die. Wipe off mold growth so it doesn't look tacky. No need to sand, disinfect, or irradiate. Mold will not live if the humidity is too low.
Yes, there will still be mold spores around, ready to grow once again if humidity gets too high, but there's nothing you can do about it; mold spores are everywhere. Maintaining a humidity too low for mold prevents mold growth.
I once received cigars with numerous mold colonies growing on the wrapper. I brushed the offending fungi off, let the cigars dry out a bit too be sure, and put them in a tupperdor. About 4 months later, the mold has not come back.
Control your humidity; there's no need for chemical warfare, and it has no additional benefit.
P.S. Distilled vs. tap water has nothing to do with mold. Any water alone, without regulation of some kind (e.g., PG, Climaxx beads, active device), will generally cause excess humidity and support mold growth.