In reply to mostly harmless:
Never found it that hard to do myself. Although being fastidious when closing the area off and dustsheeting is well worth the time taken. The kit really isn't expensive.
When i did my chimney this time, no soot escaped at all, which was nice. I find lighting a fire the day before dries the chimney and makes sweeping easier.
Just don't blame me if you have to redecorate.