For the bros visiting Seoul:
Attempting to contact escorts on Craigslist Korea is risky and ill-advised. The national police has recently set up sting operations to lure foreigners and pinch them for prostitution. Although they are mainly targeting military servicemen or expats with working visas, tourists will be immediately deported and potentially blacklisted from entering the country.
Even those business cards that litter the street offering "office-tel' girls are risky as well. Bros have discussed 'donation' over the phone or via texting, showed up for an 'incall' and been greeted by a cameraman and a cop.
Just be safe guys and stick with the trusted gals...
and a little FYI.
Heather Shimada is good to go and can be completely trusted 