If I was a professional I would pay to play with someone who can teach me, or who can partner with me on exploring new skills. Let's say I have been providing a BFE vanilla service, and I want to explore something more kinky, I would look for someone who would be a good match to do that. I think it is better than experimenting with a client, although in the right circumstances there is nothing wrong about using a client as a lab rat if I have his consent.