Thanks to the both of you!
I wasn't sure about using my breath because when I was in the army, we were told not to use spit when 'spit polishing' our shoes because the acid in our saliva will destroy the leather (or something to that effect). So I just thought that our breath will be similar. But as you are both using it with no ill effects ... guess who will be 'spit polishing' (well, not with saliva, but breath anyway) their new ereader! :P