First, I thought the initial question was an honest one and I find the answers surprising (read: dismaying).
Sure - no one is going to mention names - but surely it's no secret that you can get out there more than just a 10 minute hand job!
I'm not going to mention names either, but not because of some pretend code of honour here. The fact is, if I really liked a particular girl and got something extra from her, the last thing I'd do is advertise it. Some girls do "extras". Some do it for anyone that asks. Some do it only for a select few.
More to the point, it would come off as bragging and/or lying.
On the other side of the coin, I've had less than pleasing experiences too and I'm not about to name names either - because ultimately, even if I'm entirely accurate, I might be impacting the means of income of some person who clearly doesn't have a lot of alternatives open to her, and in spite of the fact that I had a bad experience, I'm not into revenge.
Frankcastle asked, "What's special about you?" Well, there's lots special about me, but really the question is beside the point. Sex is 50% physical and 50% psychological. All of us could save the bucks and masturbate. But we get turned on by the psychological too. So I perfectly understand the desire to get more out of a girl than a quick hand job. Some of those extras come with risks, some don't. In some cases you can prepare for those risks (by bringing a condom, for instance).
But I understand completely the wanting of more - it's only natural! You've got a hot naked girl there - who wouldn't want to stick your tongue down their throat?
Ultimately, my advice is - it's a numbers game - and be prepared to spend money. The more girls you visit, the more likely you'll find one willing to do what you want. (And don't be afraid to generalize this trait in her, to asess the risks.) Your success rate will depend on your looks, your style (don't be arrogant, don't be too intense, compliment them, make them smile, dress well, etc), and your wallet.