I have to clean the gutters every year on my rental. Some are on the second story, so pretty high.
I've been testing, over a couple of years and found these to work extremely well. A gutter that normally had 2 inches of muck in the bottom was basically clear and clean.
They snap in , have holes in them, and there is screening over the holes to stop the small stuff. They are cheap at $2.59 for 4 ft pieces.