Actually Aussie Bob, Cloud seeding uses Silver Iodine, or frozen Carbon Dioxide. not silver oxide. The Snowy Hydro scheme in NSW has been doing it for decades as well, and have recently been given approval to do it permanently after decades of studies and trials..
The reason is to increase snowfalls which average about 14% increase over non seeded areas, so as to increase inflows into its dams for more cleaner energy....
and non of its seeding is done using aircraft.