I pottied trained my son while running my daycare. I started because he was refusing to wear his diaper, he was 23 months. I was going to do it sooner, but it was Christmas. Anyways, I just put him in underwear and let him go at it. I have no carpet upstairs, so we just spent a lot of time up there with the daycare. He also rarely plays with the other children and plays with his older sister, so he wasn't really around them. It was a pain to clean up his accidents when he had them, but he usually had them at meals times, so the other children weren't affected.
I guess I'm no help. It really didn't take him a long time to get it (about a week) and then he went through a lazy spell, but again, he never went in the area the kids were in and it was a quick clean up for me.
With that being said, I wouldn't let a dck train this way, but he's mine, so I didn't mind.