Nikki,
I guess I should have clarified that i'm using the bells in conjunction w/crate training and all the rules that go w/that. So peeing on the floor is just not allowed. I'm sure you can do a search here on crate training and get all the do's and don'ts. It's like they have to learn 1. you can't go in the house 2. you can and should go outside and 3. you need to tell me when you need to go outside. The bells are only going to help w/ #3. So if they are still going inside, maybe the crate is the way to go? To anyone who has dogs that are scared of the bells...
my bells are little. Maybe 1 inch diameter balls, 3 of them, on a paperclip at the end of a metal chain on the door. the photos people have posted about their door bells amaze me- they're so huge! Wow! The one was like a leather strap of bells that could go on a sleigh!

I mean, if it works, why judge? but they may scare off little shy dogs.
Teresa