This may be one of the reasons that a hermetically sealed blue box was designed for the 'fix'. To keep combustion gases in and to keep water vapour out.
More than that.... Their "solution" of putting a battery in a box, which looked like avoiding a problem they didn't understand.... included "drain holes" for the battery....
http://assets.sbnation.com/assets/23...on-English.pdf
Maybe Boeing had worked out what the real problem was and that's why they were so confident that it wouldn't happen again.
Perhaps they could buy some more boxes to put electrical stuff in.