You don't have to use a Cherry Pitter to pit cherries, but is sure makes the job easier. The first time I ever attempted this, I did not have any kind of pitter, so did this by hand.
If you are wondering how to pit cherries without a pitter, it really isn't very hard - it just takes quite a bit of time. It seems like you have to go through a lot of cherries before you have enough to make any kind of dessert.
I used a typical office paper clip and bent it into the shape of an 'S'. This was inserted into the cherry to remove the pit. Once you get the hang of it, you can move pretty quickly. Wearing gloves makes this a little more awkward, but it sure helps your hands from getting stained.