Feathers of Boop work nicely as well, being a defused variant of the Feathers of Doom - the best mass destruct weapon against the Seekers... But I won't tell more yet, to avoid a major spoiler for the book.
Main thing - the projectiles grow back fast, so I'm not risking the glory of mine wings
And Dash can argue with Whinestein as much as she wanteth, I still prefer solid projectiles...
*boops @CypherHoof once again, just in case*