To form the rice balls, line a small cup with plastic wrap, sprinkle the plastic wrap with a dab of water, then fill the cup 2/3 full with rice mixture. (101cookbooks.com)
Trim the edge to make a perfect circle, and use the trimmings to fashion a ridge around the edge: wet the outside edge of the circle with a dab of water. (emmafrisch.com)
You can also apply a dab of water - based lubricant to the opening of baby's anus. (thebabycorner.com)