Have you succeeded doing it for more than one person, We tried it and it didn't work so it was easier to do one each but there do seem to be a lot of glitches with the system.
Hua hin is widespread with many different types of locations, from City to rural living, spend your time wisely looking at all areas as a 3 week vacation is very different to full time living, here's a guide to Hua hin which may help you