Turning back into people isn't going to fix the tiny minor-itty bitty little petrification problems anyone who got hit by the Prince's poison got stuck with, unfortunately! The Ringmaster will be using her powers to grant the partly petrified the ability to move normally, but she won't be able to return them to normal instantly due to the difficulty of working with stone. Ginko and Peridot have both discussed the idea of addressing poison issues on the radios, but this is a more formal attempt to feel out who'd might be interested in their characters being part of an effort working towards a cure/providing moral support/being guinea pigs to make sure the remedy isn't worse.

Due to the nature of the poison, It'll likely need combined magical, chemical, and ~spiritual~ expertise on the job. Either way, it's going to take some work!