I think it is definitely more complicated to fix hygienic behaviour but it is a worthwhile long term goal.
They have had some success in the US. Harbo and Harris and Marla Spivak would be some of the names to google.
There are breeders in the US selling hygienic stock.
The native Irish Honeybee Society has started a project to look for bees which deal better with mites and hygienic behaviour is going to be a big part of that. A funding application has been submitted from Galway University to develop this work but no word back yet about whether it has been a successful application. Fingers crossed.
In an ideal world we would like to be selecting for more resistant stock from within the existing population. Apparently this hygienic trait is present in all be races to a greater or lesser extent.
But anyway, back to the choice of books as the thread is going off at a tangent! (again)