Quote Originally Posted by Highspeedmonkey View Post
a mammoth clean up awaits after treatment.
May you be doing it on a reasonably cool day.

Here's a thought - If you use glue board ILTs instead of the zappers, there wouldn't be quite as much splatter to clean up

Probably be an issue with summer time temperatures in the roof, but I see the cluster fly migration into the roof void tends to happen in autumn - so perhaps still an option.