We used these for Teddy so my son and Teddy would both be wearing "big boy underpants". For my son, I used the absorbent and waterproof PUV type with regular absorbent underpants underneath. That combination was good for about one pee, but they did leak so an immediate change was necessary.

At any rate, the plastic underpants were great for Teddy! I wouldn't use them alone over regular "absorbent" training pants though, because a second layer of aborbency is needed. They might work well over cloth diapers, though.