Any particulate material will do, just remember you are breathing the stuff. Most commercial spray powders are corn starch, I am wary of inhaling much of the other types of products.
the rule of thumb is to use a spray powder which has a diameter of one-tenth of the GSM of the stock, eg 200 GSM use a 20 micron diameter powder
each type of natural starch has a different diameter, so you will find that the best suppliers such as Archem in the UK use corn, wheat, samolina, potatoe etc
printers nearly always use too much powder but even so the cost is minimal for a stack of paper, so why use rubbish, invest in an an ultra-low dust product which will save time in press cleaning and give trouble free running on Weko and Graphix spray guns