we use drain rods with a gutter attachment
Can you be a bit more specific? Maybe a photo or two?
Only gutter jobs I've ever done are on bungalows and it's been really time consuming:
Stage 1 - up a step ladder, and a trowel and bucket job.
Stage 2 - on the ground, and wash with wfp
Stage 3 - back up the step ladder and do the fiddly bits right behind the gutter and up inside the brackets with a microfibre.
(That's why I've only done bungalows - no way I'm working off a ladder at ten feet.)
I'd priced well, but finished up making a crap hourly rate because it took so long.