my 8 month old daughter is diaper free. equivalent terms for diaper free are natural infant hygiene and elimination communication. the pediatrician on this segment who referred to natural infant hygiene as "aggressive" is not referring to diaper free practice but to early potty training. diaper free babies are not potty trained in the typical american way. there is no negative reinforcement. our method is simple: respond to babies' cues that they need to eliminate. nothing is forced. if babies don't want to go, they don't. we simply provide opportunities to pee in a potty rather than in a diaper when we see that our baby needs to eliminate.
it is as straightforward as this: you see your three year old assume a squatting position and a look of concentration; you ask if she needs to poop; she says yes; you offer her the potty and she uses it. babies have their own way of communicating their need. they squirm or cry in a distinct way. you learn their signal for elimination just as you learn their signal for being tired or hungry. you can practice this in conjunction with diapers. this is a way to respectfully communicate with your baby. babies are indeed fully conscious of their bodies and fully capable of communication as well.
try it, and you'll see. if, instead, you ignore your baby's elimination cues, they will give up trying to communicate it to you.
go to www.diaperfreebaby.org for more info.