First, make sure they're getting plenty of exercise. A bored dog can be more reactive. When you treat for calm behavior be sure you do it right, some people hear the dogs bark, call them and give a treat for being quiet. A lot of dogs play games with this and bark then run to you to give the treat if you don't fade correctly. It's best to find a friend to ring the bell. The thing with the quiet and interrupter is that the dog still barks until you use your tactic -- I don't really like that. You may have to do what some may refer to as "flooding" the dogs. This was the only way to get Baby to stop barking. Even if I redirected him he would keep barking as he went to his crate. A lot of dogs bark because they associate the knocks and doorbells with guests. So thus you "flood" with the doorbell. The first day I rang the doorbell 400 consecutive times ever 3 seconds (so I spent about 20 minutes pushing the doorbell). I told my roommate on the inside to let me know when Baby was quiet for 20 consecutive rings. Once he finally was I ended it. I disconnected the doorbell for the reset of the day so people couldn't undo my progress. The second day it took a little over 300 tries for 25 no barks. It took about 6 days to make it solid. After this I would every now and again ring the bell when no one was coming in so he didn't bring back the bell with the association of strangers, maybe 1 in 5 rings would be someone. Don't let guests look at your dogs until they have all settled down. Even when I come in the door I ignore my pups until they're calm. Your dogs may not take as long as mine, he was pretty dead set in his ways. Also, dogs can easily build off of each other's behavior. I kept Chaplin tied in the yard every time I worked with Baby.