A really useful bit of kit in my opinion is the Gutter spike. It is used when the material within the gutter is too dense or to large to be either vacuumed or flushed with a high pressure jet.
They are not expensive to buy. (Only supplier I know is Omnipole) and believe me they are worth their weight in gold. If you have a quick connect gutter bend (walking stick) gutter cleaning attachment then this tool will fit (either Omnipoles power pole or Northern tools fiberglass telescopic lance version).
The pole and set up in the pictures is Omnipoles own powerpole.