Looking at your ad, my two cents:
* I would remove the negative statement, "I do not accept..." and just state an hourly minimum (positive statement)
* I would remove the negative statement, "My rates are not..." - to me, this statement sets the "overpriced" idea in their minds... instead use positive descriptives to describe the BBW experience... top-notch and finest definitely are working... also: delicious, satisfying, relaxing, etc. - set the expectation.
The only "negative" I'd include would be a statement such as "if you're looking for spinner, etc etc, then I'm probably not for you" - that way you're essentially psychologically rejecting the asshats before they cant reject you. And the BBW lovers (the clients you WANT) are reading it and like "yeah, I'm here for ya baby! You're just for ME!"
Ms Mocha does this beautifully
* also, I don't give out my phone until after screening is complete, and so far it seems to work for me.
My humble opinion, offered with a gratuitous grain of salt