After some tests, it looked like the viscosity setting for emitterB was simply overridden, so I set it so something nuts, like 5000. That didn't do anything either. On a different computer/ OS it was the same, so I thaought this might be bug.
As I got to know- it is not:
Here's what Gus wrote:
Probably there will be support for this in a future version? Until then, we have to do it in the "old school" manner, via Python or C++.(...)Particle attributes are passed as is from the original emitter to the
target one, so at the moment that is not working ´cos it should not.(...)