Getting up close and personal. lol

While at the vet, I learned that I will need to rub the kittens butts to help stimulate them to..uh.. go to the bathroom. This isn't one of the finer parts of raising orphan kittens. lol So I grabbed an old cloth and some warm water and set out to do this not so fun job. As I started with the first one, I had to apologize that I was getting up close and personal with them despite us hardly knowing each other. lol I had no idea how to rub their butts when I started with the first one and I was somewhat unsuccessful. She/he also didn't appreciate it much. By the third kitten, I like to think I got the hang of it though because all of a sudden it started going pee and I had no idea if I should continue rubbing or stop. I thought it was coming out good so all I could think of to do was hold it upright so the pee would dribble on to the floor where I had a rag that could soak it up. I am guessing it didn't feel I was doing it right and was complaining the entire time. Yet it did seem to get that look of relief on it's face when it was finished. lol The others didn't really do much so I hope it isn't my lack of expertise in this field that caused that. Any input on the proper way to do this is much appreciated!! Is there a technique to it? I have no idea. I am starting to really appreciate mama cats and all they do to raise their babies!