I have found a great way to clean out my pellet stove pipe by using a leaf blower. This method really gets all the soot out of the pipes. It also gets ashes and soot out of the back of the pettet stove as well. I try to do it after every 1/2 ton of pellets I burn in the stove.
All you need is a leaf blower that has a suction section on it. I am using an electric leaf blower that I got at Walmart for $40. To connect the leaf blower to the pipe the first thing you need to do is remove the rain cap from the end of the pipe. You need to make a seal onto the end of the pipe from the suction section of the leaf blower. Some people use PVC pipes as adapters, I just use a bunch of duck tape.
So pretty much all you need to do is attach the leaf blower to the end of the pipe and plug it in. You will see a lot of soot shoot out from the end of the leaf blower. Make sure it is not pointed near anything important because it would make a mess of it. This is grreat for cleaning out all the pipes in your chimney. You don’t need to take them all apart and put them back together to clean them anymore. It also cleans the exhaust of the stove itself. Just watch the video on this page to see it in action.