Boiling water has probably been used to clean pipes since ancient times. Certainly this girl had to use more than just a stick to clean parts of this baby.
Furthermore, water is free and easily accessible. The first time I ever really cleaned my pipe, I used this method.
First, get a pot big enough for your pipe or pipes (you might as well take this opportunity to clean all your pipes. Also, choose a pot that you won't miss using for cooking. I have found that it is harder to clean the pot you use to boil the pipe in, than it is to clean the pipe itself. And you definitely don't want your mom asking you about the black tar-like stuff stuck to her brand new pot from Crate and Barrel.
Fill the pot about halfway with warm water. Put the pot on the stove and put your pipe in it. You don't want the water boiling first, because then you have to drop your pipe into the water, which could be dangerous for you and your pipe.
Turn the burner on medium, and allow the water to boil. At this point you could use a pair of tongs to move your pipe around a little bit to loosen up all the resin inside.
After 5 or 10 minutes of boiling, take the pot to the sink and turn on the hot water. You want the water hot to help you rinse out the pot of now resinous water. The water needs to be hot to keep the pipe hot and avoid cracking due to temperature change.
Repeat the last two steps a few times or until your pipe is sufficiently clean. You might also use some form of pipe cleaner (or wire) at this time to get those hard to reach places. Just make sure you have poured out all of the water from inside the pipe itself and use a towel or oven mitt to avoid burning yourself.
If you're cleaning a glass pipe you need to be particularly careful using this method. The hot water is not necessarily dangerous for your pipe, but you could burn yourself and then drop the pipe. You could also drop your pipe into the sink when changing the water.
When you've finished, give the pipe one final rinse, allow it to cool, and enjoy. Keep the pot (the pot you used for boiling the pipe) for next time. And check out http://www.kashtray.com/ for an interesting new product designed to keep you pipe clean and clog-free every time you use it.
Check out our article on cleaning your pipe with isopropyl alcohol.