Yeeah! I feel that Kia is reliably potty trained now. That is, if I give her an opportunity to do her business before entering an establishment, I'm fairly confident we can go through the store without incident.
Until Guide Dog Puppies are reliably potty trained, we only take them in places for about five minutes of socialization. We also watch them like hawks, because it isn't good for relationships to have puppies piddle in the library or grocery store. There are invariably accidents, so puppy raisers almost always carry duty bags, wipes, and paper towels.
How do we train the puppies?
Well, the first thing we do in the morning is to pick up the baby out of their kennel and carry them to the backyard. We snap on their leash, put the pup down, and say "Do your business." (I say we, but I'm making Anna do this part, because that's just too early for me.) Pups are generally eager to do their business first thing in the morning.
Then we feed the pup and give him water. And we play with the pup or work with the pup. We watch the pups closely and if they do a puppy potty dance, we take them outside, on leash, and say "Do your business." If they don't start the potty dance, we put them in their kennel when we aren't observing them carefully. Pup goes to nap, and when pup wakes up, we repeat the procedure.
Guide Dog Puppies seem to get the idea of what's expected of them after just a few days. It takes their bladders a while to catch up, however. Kia was like that. She got the idea fairly quickly, but it took a while before her bladder caught up and before we recognized her signals. Also, she had to learn to make her signals obvious to stupid humans. Her most common signal now is to sit by the backyard door.