Actually I was chatting with a lovely woman at Platinum, I think, a few months ago and I asked her what sort of sessions made her uncomfortable, and she mentioned sessions like these.
She DID them, but she found them a bit awkward.
My guess is that pretty much ANY MPA will do the session you like, just don't expect her to like the session.
There's a beautiful MPA at HFH who happens to have beautiful feet if you're into that kind of thing, and she's told me that she does indeed do foot fetish sessions, but she absolutely doesn't understand what the deal is.
If it's just about paying someone to act, honestly I don't think you'll have much of a problem once you swallow your pride and ask for what you want. Better yet, ask the ladies who run the spas (Kayla at HFH, Joy at SRM, Tia at Platinum) for a recommendation - they've heard of way weirder stuff than the weirdest shit you can dream up.
If you actually want a woman to get INTO it, you're fucked. These woman have a hard enough time pretending that they're turned on while you're licking their clit with a finger up their ass.
I mean, gently kissing the nape of their neck while drizzling rose petals on their torsos.
Or whatever you're into.
