Why we clear by hand instead of using a blower
A blower is faster and that is the only thing it is better at. It pushes wet silt into the valleys and packs it into the top of the downpipe, which is the one part of the system you cannot see from the ground. The gutter looks clean and the blockage has simply moved somewhere less convenient. Clearing by hand means the debris comes out of the roof entirely, and the flush afterwards proves the line is actually running.