Yeah, with an unknown effectiveness. Like, maybe it will rain 5% more, maybe 5% earlier, but no guarantees. But, despite that, it's widely deployed just in case in some places.

And if you seed open air with silver iodine nothing happens, which is why you can't use that to, for example, make rain in the Sahara.

You need clouds already up there for it to work, which means water vapour getting up there in a high enough quantity that it has liquidified again (that's what clouds are: lots and lots of tiny water dropplets).

So what exactly is the geoengineering process that's put all that water up there in such quantity that there are clouds all the way to the horizon on all side, so thick that the sky becomes dark?

Our capabilities are about the equivalent of taking a bucket of water from a "creek" passing by in the sky whilst this hurricane would require us to be capable of putting an ocean of water up there, which is nowhere near our capabilities.

Ok now make a hurricane