first of all, NEVER EVER give a deposit.

secondly, don't go Asian. most have a pimp.

when using Locanto, usually i click on the name and see how many ads this person has. if multiple ads, it is most probably put up by a pimp, in which case, stay away.
text the number in the ad and ask for a pic. if the pic is any different from the one in the ad, stay away.
look at the reviews. anything less than 4 stars, stay away.

make a booking. show up knowing there is a possiblilty it is a waste of time and be prepared to walk away. if you stay and it turns out to be a dud, it will be a waste of time and money.

i mostly make multiple bookings with different girls, one hour apart so i know i can always turn around and go on to the next person.