Hi Sam,
I echo the sentiment that it's great you are out spreading the joy of astronomy with others. Keep up the good work.
The only thing I can think of that may help with focus is to maybe look into getting a Bahtinov mask. They can be either brought commercially or there are a number of websites that can generate a template to make one yourself out of some card or other material.
They are in general designed for focussing on a star but once you have the correct focus on a star once you swing to a planet they are generally pretty close to the same focus.
I think it would be acceptable for visual observing anyway.
http://astrojargon.net/maskgen.aspx?...ookieSupport=1
http://en.wikipedia.org/wiki/Bahtinov_mask
I hope that is of some help to you
