I've been following the gutter scoop threads closely recently,.. some very good ideas coming up (maybe not so much this one!).
I've been wondering,.. since many gutters are different shapes/sizes etc, a hard metal/plastic tool might not be the most effective solution.
I did some gutters a couple of months back (off ladders for shame) and there was one long section above a single storey pitched roof garage that I couldn't reach. I used a spare pole with an old brush to "drag" the debris back towards me, and was surprised by how effective the brush was.
Perhaps a tool that is either a shaped brush, or slightly flexible rubber/plastic that will shape itself to fit the gutter would be effective? Drag all the debris to one end and then use a different tool to "scoop" it out?