At the www.justmanbrush.com
site go to the industrial tube brush collection and get are the following diameter 1/4", 3/8" and 1/2" with the 24" or 30" handles for the last two and a short 12" or so handle for the first. The brushes are very high quality and a good value. When you clean mix baking soda and lemon juice until it has a consitancy like toothpaste and just stuff the stuff into you stem scrub the insides with the brush. Run a bunch of hot woater through the stem and repeat as needed.