How do I sail rafts in Breath of the Wild?

There are a bunch of rafts around Zelda: Breath of the Wild, but they don't seem to be interactable and none of the NPCs so far have mentioned them. Have I missed some clue or interaction which makes them usable, or just do I need to use something weird like time freeze to move them around?

Turns out you have to use some non-Newtonian physics to move rafts: while standing on the raft, wave a Korok leaf at the sail or push an object held with magnesis against the mast. I could not get the magnesis technique to work with a sword, so either it's been patched out or only certain (heavier?) objects work.

Get a Korok leaf and stand on the raft. Use the leaf to blow gusts of wind at the sail. Doesn't make a whole lot of sense and works a little janky but that's how I got around on them. I think this is the only way to get to a certain island as well.