Wet or dry supers, in my opinion, has little effect on the wax moth.
What really does attract them is pollen stored in super cells, which may
be left there after extraction.  The second most attractive comb for
moths is one in which brood has been reared.  That is why I always use
an excluder under the supers, and in case of damage and the queen
somehow does get through, that excluder is used ever after only as a
mouse guard!

On the subject of open bee cleaning of wet supers - this is what I have
done for 20 years without any moth problem at all.  Before that I used
to stack them on hives for cleanout.  But I found as did Ron that often
in a good year honey and even brood might be found in these supers
later.  That never happens in a separate stack.  What about robbing?  A
weak hive might be robbed, but not strong ones.  I even have about ten
two frame nucs in the yard next to which I set my supers for cleaning,
but none was attacked except two that I opened and attempted to
combine.  Even that was solved by grass packing of the entrance.  I
much, much prefer dry supers stored in my barn to wet ones.  (Bees,
yellow jackets and mice don't come snooping around as much.)

Ted Fischer
Dexter, Michigan USA