How do I dry up a stucco wall that presents efflorescence?
Here's what comes to mind:


Increasing air flow, using fans - on both sides if possible.
Applying a product that will extract the moisture (sorry, no idea if such a product exists - maybe someone else knows of one).
Increasing the heat of the area to encourage moisture evaporation.  This can be accomplished with conventional heaters, heating bars, or using mirrors to redirect the sunlight.


Combining the ideas may increase their efficacy.

Please note that I do not consider myself to be an expert on this matter.