I ordered an organic toilet brush from Greenfeet.com which I finally used for the first time with much success. The brush itself is made from coconut fibers, which are said to clean better than synthetic fibers, and the handle is made of wood, making it 100% biodegradable.
What annoyed me the most about conventional brushes, beyond the material they are made from, is the heads were too big to fit down the hole of the commode. This new organic brush is smaller and fits perfectly, ensuring complete access to all visible portions of my toilet.
It is infinitely better than those ridiculous disposable brushes that do nothing but add waste to landfills.