Short of your spilling liquid on the tab, or using it in a steam room, I can't see how it can seep in between the two glasses. Anyhow, I think you would have to take apart the tab before you can remove the moisture.
If you're willing to do that, and the display assembly is original, the lcd is taped to the back of the digitizer. Since the original double-sided tape is not porous enough for steam to filter through quickly, heating the glass from outside will cause the moisture to evaporate, and condense into drops again at the top of the lcd.
What you need to do is slice a small opening through the tape at the top so there's some space between the glasses, then heat up the front surface. Once the moisture's all gone, press the glasses back together gently. It doesn't take much pressure for one to stick to the other. You want to close the opening to prevent dust particles from getting blown in. That should take care of it.