Hmm...
I think the best one to take next would be Applejack. She could probably be brought in easily by 'encouraging' Rainbow to talk about how 'rough' her new job is, with the implication it's too tough for AJ.

Then Rarity could be 'consulted' by Fluttershy because her 'new boss' is looking for help redesigning the uniforms for his workers. That would easily get her in the door, and as long as it's not a day when they're 'open', he could probably get her to put on the mind control collar as part of 'trying the outfit on to see how it looks'.

Pinkie would be almost too easy. Once the other four are in there, just invite her to a 'theme party' they're throwing for her at the establishment. Heck she'd even be easy to tweak while still remaining mostly herself: just add 'casual submissive sex' as something that's supposed to happen at parties in her mind while under the collar, and she'll indulge anyone as herself while on the job.

If you incorporate 'Legends of Everfree', Sunset could possibly see in the girls' minds something of what happens at work, but refuse to believe it was actually real at first. So she follows them there only to see it is real, and then Calm gets the other girls to hold her down while the control collar is forced on the first time.

Then once Sunset is completely 'tamed', have them invite SciTwi to attend an 'office party', where the control collar is given to her as a 'Friendship Gift' since they all have one, so they're a matched set. Only danger there is flipping SciTwi's switch might let out Midnight Sparkle, who might have her own ideas on how to run the cafe.

I'd love to see Sunset get pulled in to this. Plus as she is sort of the de facto leader of the group and aside from Sci Twi, the smartest, getting her taken care of early would make Calm's job a lot easier in the long run.

collars who turn people to toys is sick and slavery not cool

any idea when we can expect an update and new chapter?

Dead

9769441
Given that the author has effectively abandoned their account (or at least, that's what their last blog says) my guess is never.

If it’s been abandoned… anypony (or dragon, it is the devil speaking by the way) want to pick it up and continue it for us all?