Bests & Worsts Reviews from Amazon

After three weeks of hope (I really wanted these devices to work), I can tell this device didn't commit its mission. I checked if in any way it was doing anything, and well, yes. I've used them in the "blue" setting, and I can tell this device emmits an ultrasound, for around 5 secs, each 3 minutes... So, yes, it does emmit an ultrasound. Which is around 20000Hz... What's wrong then? Well, the roaches kind of like that frequency? Because they started to appear cuddling under the devices (I bought two)... Any size, in pairs and loners... I started to find roach's feces in the device!!!! So, it does exactly the opposite it's supposed to do: "it attracts creeters" I'm returning both... Disgusting experience :(