mass update hair_tie_in_mouth -> hair_tie mouth_hold
Save for a handful (literally, there's like five false results in total) of examples with cigarettes, the hair_tie mouth_hold search is already an equivalent of this tag. It seems unnecessary to have a tag for this, especially since it doesn't even include hair scrunchies.
EDIT: The bulk update request #1691 (forum #147365) has been rejected by @nonamethanks.
Updated by DanbooruBot