In the Valley I would think it is a hard find.
1- Most of the girls don't stay here long enough
2- MMS and the owners are not going to let money walk out the door
3- Not many of the girls actually drive. If you ever talk to them about how they got to the spa the answer usually is $200 taxi
4- Legal status generally doesn't allow them to wonder too far from spa
This is for the Chinese and Korean places, not sure about the American girls.
It's difficult, but not impossible. It does require time/money/effort to get to "know" the providers. The Big Boy Wallet comment is in effect, but not the way you might always think. The best ones are freelancers, they work for a spa, but are totally free to move. As long as they are on "vacation" the spa has absolutely no control. International travel is limited (unless you want to go to Korea or China). Domestic travel is totally appropriate, if they trust you. An offer to visit Miami, Hawaii, or South Africa will peak interest. Even if it ultimately becomes just a few hours/days in a "nice" Flushing hotel, you have to be willing to make it happen. Once it happens, depending upon where you go, other "services" are literally free!
Be a gentleman. Opening doors, taking the check, paying for excursions, etc., will all but guarantee a repeat performance! Many do not mind HOURS in bed. After all, it's only one guy who they actually like being with. Their gratitude is immeasurable!
That's all I have to say about that...