Here is my take on teaching when to hold it. kash has finally gotten it. However they need to be on a strick schedule.
You wake up first thing you do, is outside to potty. No coffee for the Aqua family not morning newspaper. Then IMO you would then feed them. Get ready for work walk them again before work. Then not sure who is home mid day but someone walks them round the same time everyday. You get home, walk them, feed them. then right before bed, walk them again.
That is my schedule. They eat at night - they are on raw. I know they do two poops in the am. One at 5am, the other round 7am. Then they normally do both for the dog walker, and then a small one with us at night - during the week they only get walked.
5am
7am
noon
3pm
6pm
10pm
Thats it. They are sooo good to the schedule that there are no issues. Weekends are difference since its not set, but if you observe the dogs, you know when they have to go, and not just when the ring the bell to go out. By them constantly ringing the bell - its great they are telling you, but you are falling subject to them allowing them to control you, and not you control them. And if you take them out every time even if you know they dont have to go, they are totally playing you - dogs are smarted that you think!!! ha ha
So establish a routine, dont give them full roam and if they dont do well, then they are not ready, go back to basics and get out the crates.