since you're in San Diego, sting city, you need to stay with providers who have been reviewed numerous times.

LE in SD could set up their own massage place and sting you.
You are also far more likely to be ripped off in San Diego. Look at the ripoff board for examples.

You must use the Search function. Look for what you want, and someone who has been positively reviewed 3X or more.
Do the search. It brings up over 50 hits! These are a few, but go read the reviews to avoid surprises.

Heavenly/Chassy, Joy, Lana, Syra, Erika, Meagan Lee, Kris,
Misty & Barbie, Sonata, Cher.

I did not look at the reviews, but only plugged in 3X+ reviews, c-bbj. So you   have to do your homework still to eliminate trogs and poor service. LOL

Arranging an appt. over the phone for a "sensual massage" (no description of activities).

Legal danger?  Come on!

Suppose the answer was yes - you have to actually go to the appointment.  How would that information be of any use?  Why would you make an appt. if you don't plan to go to it?!

Dont have any legal advice , but from recent experience I can tell you what I do.
First of all use TER for what its purpose is , qualify whouyou are calling.
If you are interested in seeing someone who has not been reviewed, be extra carefull.
I will make appointment with the provider based on her review's, I will not mention her reviews unless she brings them up. I will not discuss hourly rate, no reason to, cuz you know what it is. I will not discuss any services, no reason to, I know what she provides. I basically try to set up the appointment  and that is it! If you decide to see someone without reviews you may get burned for cash, cuz you dont know what you might get if its an agency. If its a LE setup then you save yourself from a sting. In either case show up and carry fee in envelope , I like to set it down with my wallet and keys in plain view. Do not discuss activities just let the appointment take you whereever. If the appointment goes as planned pick up your belongings and leave the envelope. If she asks if the envelope is for her you can give her a nod. If she needs to count it and puts it away that is cool. I worry about LE stings and recordings so keep the conversation to a minimum.
She may ask you about the amount, you should nod if she states a number. I try not to discuss $$ at all if possible.
I never discuss any illegal activities especially if she asks what you want. I just say lets see how it goes. Just take the lead or let her take the lead and follow.
Conversation can be dangerous on a first meeting, even if she has reviews. I was recently busted with someone who had 4+ reviews in O.C.. My case was dismissed , they had no evidence. I understand LE will lie and fabricate, but how can you defend yourself against that. Just dont give them anything to expand on. Just because someone has reviews doesnt make them 100% safe especially in o.c.. Check out the reviewers, cross check them, if they have seen someone you have seen quiz them.
I will wait to see if someone credible has reviewed in the past and email them about common past appointments.
You cant be too carefull in o.c.!!!!