You can date a
spa girl outside. Many of us have/do.
Be prepared that she wants a "sugar daddy".
You will need to be ok with her "Job" and not get jealous. If you are jealous she will end it. They 95% of the time will not stop working, unless you provide them with an alternate means of income = to what they were making in the
spa (unlikely).
If you just want some out of the
spa off the timer fun, yes then date a
spa girl, you will be expected to compensate her the same amount as you would when she is working (in MOST cases, some will do it for less/free), but you wont be restricted to the 1hr.
Ask for her number, and call her up and make a date.
Good Luck.