I'd rather a pup remain clean and receive a gentle bath every few days than have feces/urine on them. I have never had a problem with regular baths, I used to give them almost weekly to my service and guide dog puppies in training to keep them above and beyond the usual cleanliness. When I have a litter of pups from the shelter or owner surrender that we are fostering, they get baths every few days and I've yet to have a problem with this. With puppies I use the old stand-by gentle puppy tearless shampoos, rather watered down.
I have used scented without problems, but prefer to use the tearless puppy stuff. I've never bathed pups in "people shampoo" but I'll tell ya what, I bought a big thing of the human white rain shampoo, I think it was tropical coconut or somethign to that effect, at the dollar store nearby and have used it on several of my adults for the past couple months. It has worked BEAUTIFULLY. They smell great, their skin and coat is nice and soft, and they don't get any itchies (I have one prone to the itches a few days after baths due to skin drying).
I've used all sorts of medicated shampoos, the traditional "oatmeal" shampoos, and tons of different brands ranging from $5 to $15 a bottle. The whole pH thing one always reads about boggles my mind, because most bottles don't even TELL you the pH so it seems like one of those things that just gets passed along to other dog owners with no real proof. If the pH is different, where's the proof that it is a problem?
Personally, I tend to go with what works best for me and my dogs, and if it goes against the grain, so be it.