Just a quick follow up on this because I finally got around to sorting it out and in case anyone else is running into the same issue. After a bit of stuffing around I realized there was an issue with the commands, they needed some extra quotation marks (as per @PitaJ 's suggestion):
zrem registration:queue "Hermina\r\n"
zrem registration:queue "Kallie\r\n"
This got everything sorted. Appreciate everyone's help!!