I have a bent Dr. Grabow. I have to let it cool after smoking, remove the bit and get the pipe cleaner down in there that way. I just cannot, for the life of me, pull it off by just pushing the cleaner through the business end of the bit like on a straight pipe. I'm sure someone more helpful will chime in :help:
This is probably the obvious which you have tried, but when I have trouble getting a pipe cleaner through a bent stem I bend the end of the pipe cleaner which is sticking out of the stem to make a little crank and crank the pipe cleaner. This usually will get it through. Another thing that will help is use a bristle cleaner. They will go through more easily and will solve the fluff problem.