I have been a longtime chatter in various formats for nearly as long as chat capabilities have existed in cyberspace. Whether you need simple regular chatter to drive activity, or specific engagement with individuals, I'm your guy. I do have some questions regarding what level of engagement you're looking for, and what level of activity you're looking for. I'm assuming that, since you're not looking into botting, that you do want some level of specific engagement.
I have a brief history in writing erotica, so the idea of working in an NSFW environment is hardly much of an imposition. For what it's worth, I have several friends that also work as models on the site, so I do have a bit more than just a passing familiarity with the industry in general.
I have one final question, as it relates to how you worded something in your advertisement. As you are looking for someone with knowledge of the industry and upselling, is this a case of looking for someone to serve as a stand-in for the model? If that is the case, you really have found the right person in me, as this is something I have experience with already. It may be necessary to get a feel for the model's personality and typing habits, but that is a fairly simple thing to recreate.