I don't feel comfortable going out wearing a big baby outfit but at the local AB/DL gathering here, when the header of the group holds public gatherings at places, or the other guy, some of the AB/DL's come dressed as big babies and I always come in regular clothes.
Last Saturday I go to the Easter Egg Hunt held for us AB/DL's and some of them were dressed up in big baby clothes or little girl clothes and had bottles and pacifiers with them. This was in a public park where we can be seen by kids. We don't get any stares or attention from anyone and no kids seem confused if they see us. They have no reaction.