I have made rainsticks that sound great. I used mailing tubes and cut very
thin dowels to the width of the tube. Then I drilled holes (the same size as
the dowels) all over the tube. This part was a bit labor intensive, but very
worthwhile in the end. We just fed the dowels into the holes until they came
out the other side anywhere. This made a crisscross pattern on the inside of
the tube.
We filled them with a mixture of rice and various size beans. We topped them
off with a circle of cardboard to cover the open end and secured with tape.
The kids painted them with acrylic designs.
They sounded very good like the real thing.
wizzle