Why haven’t we explored the alternatives to air travel seriously before? Luck, really. It certainly seems that the growth of the global aviation industry has taken place at a quiet time for Iceland’s many volcanoes.
Chances are they can take orders, serve, clear and be reasonably attentive...But if schools and parents forgot to teach the finer points of etiquette, you'll have to be coach, tutor and guide - you set the standard. Walk it through and practice the words, don't just write it a list: most learn best by doing and talking, not reading text books.