Hi,
Agree with Jim, but my don't use flour, baking soda, sugar or other common kitchen items because they're edible for insects/bugs. Glass micro balloons would be my recommendation - snow white, looks like snow and non-edible. Expensive if you need a lot though. I'm not an armor builder so take my advice with a grain of salt (but don't use salt for a snow substitute).
PS A big welcome to the forum.