I think you are referring to "Once Upon a Potty"?
http://www.amazon.com/exec/obidos/tg...glance&s=books
We got the boy passed down to us with his diaper. Not a pedophile here, but his penis *is* really cute :LOL It is only a small cloth doll that sits on the potty, though. Some kids like the dolls that actually pee better. We got the book at the library--- in fact our library has a box you can take home with like 10 potty books, the dolls (both boy and girl) and the potty itself (it is a tiny little plastic thing--- like the small baby bjorn potties).
DD was not influenced by it at all. She potty trained as a birthday gift to me (THANK YOU DD!). I think that if DS got the doll and was left with it and the toilet, there would be one whirlpooled naked baby :LOL
The illustrations in that book, I did like. There is one where they bend over to show the kids butt that is hillarious--- just a tiny star shaped hole!