i wonder if it'd be easier to use with some sort of gear assembly and then a foot pedal or something - that one handed rotational method looks really tiring
Did you not think of the possibility of making one?
The dude has bricks, charcoal, twine and all sorts of things that he's made that don't "grow on trees". I don't think the idea of carving a gear from wood or even trying to cast one in ceramics is an impossible idea.
Probably less tiring than the alternative method with pulling the strings. With the new setup you could build a little platform over the blower so you could sit on top of it and save yourself from extending your arm so much.
The biggest problem with this setup is making the blades as close as possible to the walls to reduce drag and eddys.