While I can't be of much help to your original question about how things are in LA (sorry about that!) I can say that unfortunately, the undesireable callers and the providers using code words can be found wherever you go. I feel for you for having had to put up with so much of that already. There are several ways that I have combated the problem. Some of these things I did in the past and some I do currently to cut through my own customer base...
1) Screening: screen everyone by phone. I never made an appt with someone without knowing why they were coming to see me
If THEY start asking a lot of questions about your style, regions worked, how soon you can get them in, or specifics about draping, those are yellow--if not red--flags. In general, the longer they keep you on the phone, the bigger of a chance they're lingering in order to try to feel you out for code words and other subtleties.
2) Emphasize medical massage, if you do it: Another big one. When they call, you can ask what their chief area of complaint is. Ask questions about their insurance plan's benefits, even if you don't take insurance. We're about to revamp our whole practice and website to become almost exclusively this type of practice. We'll still offer a relaxation massage, but we also add a few terms to that description, such as the fact that it includes cold light laser therapy and whatnot. They kind of get the hint.
3) My favorite - emphasize pregnancy massage. Whenever I had a yellow-flagger, I always made sure to work the word "prenatal massage" into the conversation somewhere.
4) I used to not do housecalls on anyone I didn't know. Many MTs have this policy. Even after I removed this stipulation from my housecall criteria, I was still careful about who I did a housecall for, I listened to my gut, and I never sold GCs online for housecalls. I always wanted to know who I was dealing with. (I don't do housecalls at all right now, due to scheduling constraints.)
5) I don't advertise anywhere except a couple of free listings on legit massage websites. Many legit therapists advertise on Craigslist and whatnot, but I think that's just inviting trouble. I use 2 others and while I've gotten some calls by some would-be problem people, I recognized the clues and I think they got the idea that I'm not the MT for them. I DID get some of my coolest, most loyal, and longest-running clients to date from those sites. (I also police them as best I can, reporting illegitimate therapists to the site admin - I've gotten several of them removed - it's all about keeping up the integrity of the website.)
6) Be very careful in how you describe your services. If you put a picture of yourself on your website, make sure it's not you with your friends at a bar
Watch your wording and whatnot. These days, I hardly ever use the word "massage" without the word "therapy" behind it. (I haven't had much time to work on my own website, but trust me - if I'm not following this rule myself, it will very soon be changing!)
Well, I gotta leave for class. Hope that helps!
Best of luck in LA!
Hugs,
~Jyoti