The Steens have seen these fail. The problem is that condensation gets under the protective paper that is usually laid over the top of the bales before stuccoing. There is no apparent method for dealing with this. There was no answer on this other than prompt repair of cracks. Preventing condensation or letting it out there was no answer as to which is better.
Parapets are very popular.
Sometimes they are framed, instead of using straw, to avoid the problem. I took a rubber membrane up over parapets in a house I built, but there has been cracking. The Canadian government is sponsoring a program where they are putting moisture meters in walls and collecting data. Radio Shack has some moisture meters and there is a way to build a device. There's a diagram of it on-line .