We've been infested with them for the last few days as well. I had hardly ever seen but just one or two my entire life until last year they infested my shop, this year their population looks to have doubled. I've been looking at something to spray for them, the barrier spray I sprayed for other insects, I found a few stink bugs just strolling along, right on the sprayed barrier like it was a Sunday afternoon walk, seemed to have no effect on them.
I just filled up the wet/dry vac with a few inches of water, then went to town sucking them into the vacuum, probably got several hundred in there. When they hit the water they drown and die, then I pour the remains out when I am done. Simply vacuuming them into a dry vac the stench was worse and many of them would still be alive inside.
The ones on the outside of the house, I just grabbed a cup filled with water and a dash of dish detergent. Simply put the cup underneath them on the siding on the house and probably 2/3s of them would commit suicide and dive in, the rest I simply brushed into the cup, they generally fall straight down before flying off.
Though, if it gets much worse, I may have to build one of these.