I use the rain-x stuff, it puts a coating on the windshield that beads up & the rain rolls off. It works well enough that I don't even have to use the wipers in mild to moderate rain. Don't know how your red mud would affect it though. I mean you seem to live in the rain capitol of Hawaii.
![Ha Ha :haha:](https://board.marlincrawler.com/Smileys/marlin/haha.gif)