I bought something similar when I first started, it wasn't particularly good quality the tap broke and it leaked from the telescopic joint.
What I did was take the top hooked section, bin the rest, and jubilee clip a length of standard 1/2" hose to it with a hozelock connector, Then I could fix it to a pole using some velcro straps and use it for testing / unblocking downpipes. I think I've used it once since.
However I've got a similar attachment that fits on my 24' lance on the pressure washer - now that can clean gutters out! Makes a right mess though - useful on commercial units etc