Unless you are a businessman with connections or you got local friends give it a miss. You'll meet every low life scum in the country wanting your money and trying to rip you off and ruin your holiday. Vietnam is already mercenary enough in the tourist area without you trying to find it. I had friends who went on conferences and they were introduced to amazing looking girls....which you will never find.

Thailand scene is a fucking piece of shit now. All the girls are single mothers from the countryside. They can be very good looking but the quality and service has dropped dramatically in the past 10 years I've been there. The girls have also become very mercenary. After you factor in the cost of drinks, barfine, hotel etc its not even cheap anymore but the service usually leaves you feeling cheap. Again having connections help which you will not have.

Stick to Ginza/ 5star/ no42 gladesview/ no5 marrickville/ Kyotogirl / Sakura 52 and you'll find some real gems.