This works! We have two dogs, the second of which was a Romanian Rescue that we adopted Mid-January. They tolerated each other but did have the odd disagreement. Once lockdown started we found that with having the whole family home all day, both dogs were on high alert and this was making them tired and grumpy and the disagreements escalated quickly into full-blown fights. We purchased this kit as it had the plug in, sprays and wipes – we wanted to cover all bases. The plug-in started to help straight away. Both dogs became much more relaxed around each other and us and were able to get some much needed rest to improve their moods. In the two weeks since we purchased it we have noticed a huge improvement in how the dogs interact with each other. In that time there has been one fight which took place in a room that we didn’t have the plug-in. We now spray their bedding and bandanas with the spray for night time and that has stopped a reoccurrence of that episode. The smell is not the most pleasant but you get used to it. I normally have Reed diffusers and candles or wax melts on the go anyway and they mask the smell to human noses. The plug-in is around half way down now so I would say that the 4 week estimate if plugged in 24/7 is fairly accurate.