You raise good questions about dispersants - but the fact is that they are already used, and already applied aerially. That train has left the station. Presumably someone thinks they are preferable to loose oil - although you and I might not agree with them.
https://upload.wikimedia.org/wikiped...ll_cleanup.jpg
The
news here is moving up to jet application, rather than prop-plane application. Like the DC-10 now laying down slurry in wildfires.