This card was one of the first cards to be Forbidden, in October 2004. It did not come off of the list until January 2015, ten years and three months later. As such, it has spent more time on the Forbidden list than any other card in the OCG before becoming Limited once more.
In the TCG, this record is instead held by "Raigeki", which was also Forbidden in October 2004, and remained so until October 2014 in the TCG, ten years later. "Harpie's Feather Duster" remains Forbidden in the TCG.
When counting both the TCG and OCG, "Harpie's Feather Duster" holds the overall record, as it was Forbidden for three months longer than "Raigeki".
Since this card is only played by Mai Valentine in the anime and its effect contains a new pair of wings a face-up "Harpie Lady" gets, it can be speculated that the actual anime effect requires a face-up "Harpie Lady" on the field.