buzz lightyear,
You could have sprayed your spare empty frames with Certan. Not cheap, but cheaper than the costs associated with cleaning frames, new foundation, equivalent honey costs (to draw comb) and the time needed, etc, not to mention your inconvenience. BTDT a long time ago. Soon learned the value of vigilance where empty comb is concerned.
I used sulphur strips (like they were going out of fashion!) in my stack of super frames last winter - but think the cold weather was my best friend. Acetic acid is another possible fumigant that needs regular use to avoid any damage. The freezer, if space is available, is another option for just a few frames or on a rotational basis.
Both sullphur dioxide and acetic fume are nasty substances, which need the safety precautions to be followed carefully, if you are not compliant with the use of chemicals.
Moving your colonies may not have the desired effect; the line above (in your post) is the most important factor, in my opinion.
I develop my smaller colonies earlier and any late splits are always undertaken knowing/expecting that both halves are big enough and strong enough to resist the wasps, and with the acceptance that re-uniting is a fairly automatic option should either be seriously threatened.
I would now rarely try to fight wasp attacks, beyond the normal steps to avoid it in the first place. New beeks, with single colonies, can have a much harder time.
Regards, RAB