We test obscurants on a regular basis. They have varying degrees of effectiveness and degrees of hazards. Some of the generators are pretty cool, but they expend consumables at an amazing rate, and all are still subject to wind and weather.
They should give up on all that research and just come up with the SEP field. It’s absurdly cheap to operate and is almost perfect invisibility.
http://hitchhikers.wikia.com/wiki/Somebody_Else’s_Problem_field