I don't think anything you buy in a grocery store is really unscented, even if it says it is. Deoderant, soap, or hairspray. Also hair spray is sort of thick and would make your feathers stiff, not really what you want. I use food grade silicone spray if I have to be in the rain. I have heard great things about the powder treatment. Or you could just fletch up an arrow with vanes incase it rains. Just make sure it flies the same as the other ones.

Paul