Dust War.

These seem to be humidifiers. If that's what you mean, they work at reducing static and improve air quality.  Ultrasonic units need distilled water. Do you mean purifiers? To filter dust? If so, yes, we have one in most rooms and they work as long as you replace the filters when needed.

@noromance 

yes - air purifiers from dust (fan + drum / filter + water tank) ... how much is it advisable?
... if now cleaning electronics from dust (vacuum cleaner) once a week, then how will the interval change approximately if you use an air washer? ...

humidification mode is probably dangerous for paper speakers - you need to be careful.

We use Hathaspace and Fellows and find them very good for clean air quality. I can't specifically say that I've noticed less dust around the stereo but the filters catch a lot so the dust is definitely being caught. 

Dust War??

That's DEA terms on a Mexican boarder.

Mexico is on the defensive? ...

I read official statistics - after the arrival of the states in Afghanistan - the transit of drugs to Eastern Europe increased 50 times.
During the presence of ISAF, the area under opium crops in Afghanistan has grown a hundred times, and the production of heroin - forty times.

This hasn't surprised anyone in a long time.

No doubt Taliban is actually on US budget payroll and they had been created and established to control every square inch of an opium harvest.