In my experience, after leaving a peirco frame out for cleaning, I found a
varroa mite on the frame. My bees did not have varroa. Seems like too
much of a risk to get that many bees together - unless you can be sure that
they are all yours - and free from mites.
Of course, I have also lost hives to robbing, too - but not as a result of
honey cleanup by bees. Bad management Don't intend to find out, either.
Intending stay as far from creating an invitation as possible.
Learning all the time!
Tim Rich