Silver has been believed to ward off evil spirits. But I think this is a misconception. Alchemists established long ago that silver is less valuable, less pure and in all other ways inferior to gold.
Why, then, do vrakhiri detest silver, but not gold? I believe it is because vrakhiri, as beings superior to ordinary humans, react adversely to anything that is not of the finest taste or quality.
Another example is their preference for night over day. Day is the time for work, struggle, all things earthly. Night is for dreams, visions, rest and joy. No wonder that beings so superior have developed a resentment towards the former.
Considering the above, I believe all the silver should be transmuted into gold. This way we would not only enrich Vale Sangora's treasury, but also rid us the lesser element and increase the amount of the finest one in the world. It would surely benefit us all.