((This episode response is going to just have a slight change of events for the episode to fit in. In Genie Twi’s universe, Twilight wasn’t present for these events. As I feel if she was, Rarity could of easily just wished the silly string out. I don’t think that’d be exactly hard for Genie Twi. So just pretend in this case that Twilight was elsewhere. Either sent on a diplomatic mission or she went to the genie dimension at the time so Rarity didn’t have easy access to Twilight. But she did find Starlight, and thus it’s Starlight’s attempts during the magic attempts to fix Rarity’s mane.
 
Also I know I forgot Rarity’s punk jacket. Maybe she took it off while getting into the spirit of things here
 
But anyway, for my thoughts on It Isn’t The Mane Thing About You, go here))