I've never tried it myself but I don't see why a PVC pipe wouldn't work. It would be cheap and easy to customize too. If you wanted to get creative, you can get two different diameter PVC pipes so that one fits perfectly in the other, then drill holes through and through at different heights on the bigger diameter pipe. Then find something that would fit in the holes you drilled. This would enable you to have an adjustable height for your pole by sticking whatever object through the holes at the desired height, then sticking the smaller diameter pipe in the bigger diameter pipe. Once the smaller diameter pipe hits the object you stuck in the holes at your desired height, it would stop and give you the perfect length you wanted. Again, I've never tried any of this, it's just an idea.