I've had limited success with waxmoth prevention and would like to share my
method.  I haven't used excluders until this year so I've had some brood in
my honey supers to attract wax moths.  After extracting each super is
wrapped up in a plastic trash bag and stored in the freezer for a few days
to kill any waxmoth eggs in them.  After that they are simply stored in my
garage still in the plastic trash bag.  The secret (I think) is that I keep
a bug zapper in the garage.  It's on all the time and kills any flys,
mosquitos and MOTHS that get into it.  This keeps the flying insects in the
house to a minimum.  I've noticed dead moths under it.  I believe I'm
killing them with the bug zapper before they can get into my comb.  The
reason I call this limited success is because I've only used it for two
years.  When it's been ten years without a problem I'll label it a success.
 
This is probably only useful for the smaller beekeepers out there.  A
commercial operation would need a walk in freezer that wouldn't be used the
rest of the year.  My freezer doubles as food storage for my household.
 
Ted Wout, 3rd year, 10 hives
Red Oak, TX