The one great thing I find about Vietnamese girls (which is also frustrating for every guy out there) is their blatant transparency.
Around 99% of are regular Vietnamese girls, and 1% are hookers. Just setup a profile with 3-4 pictures, be friendly and just casually ask if they would like to meet up for a coffee or dinner when you land. Just set up a number of dates and you will be fine. Even though Vietnam is considered South East Asia, and thought of in the same boat with the likes of Thailand or Indonesia, the country has far more in common with China than those regions.
This is due to 1) high population 2) language 3) it’s closed-off society and should approach the country with the same idea.
In modern regions such as North America, Europe, or Singapore, women have learned to put up “shields” over their true personalities as they grow to be an adult.
When talking to a western chick, a guy has to cut through shield after shield just to get at the root of a girl’s true feminine side before being able to take control. Vietnamese girls will attempt to lie or hide feelings you will always know where you stand with her, giving you an upper hand.
Of course, your true goal are always your own and you shouldn’t feel like acting like a white night if you don’t want too.