I haven't 6 using 1. And yes, they are all suddenly thirsty the moment one touches the waterer. It's HILARIOUS. They are definitely flock birds.
FWIW, I have only had a leaky vertical nipple once (that sounds like a medical condition...) But, it was the water bottle I had outside for years and...
You can leave the dish water option if it makes you feel better but it really isn't necessary. Just tap enough to dangle a drip and wait. Once one finds it, they all will join in. Shouldn't take long.