Dear colleagues, I am getting used to my new pipe which has a very acutely bent stem(lip and tenon form a 90 deg angle). When I try to pass pipe cleaners through it the tip of the pipe cleaner which is metal scratches the inner side of the stem, leaving some stem-powder on the tip of the cleaner. I have tried to bend the cleaner tip a bit but it always scratches the stem at a certain position. I worry that the pipe cleaners will pierce the stem someday. Are there any pipe cleaners which do not have a sharp metal tip? Any other advices on the ways to clean such a bent stem? Thanks!