Moss covered vines are a bad idea for chameleons. They tend to stay damp and can lead to foot infections. The black vines have the problems mentioned above. Clean dry sticks from trees without sticky or white sap work well. I prefer oak but any hardwood that doesn't grow nuts is fine and will last. ie: maple, birch, poplar.
I give mine a good soap and water wash and a quick bleaching and a very thorough rinse and let dry completely. The beauty of natural branches is that they are a variety of diameters so they don't spend all of their time with their weight on the same part of their foot and that can lead to bumble foot.
our cage could use a few other upgrades that were mentioned as well. You might want to get a husbandry review.