1 My guess is it's dead easy to invite a guy for a meal, feed him and part company. [I have no interest in this, but respect different choices]
2 To find a guy to act as the top, without any kissing might be slightly more difficult. [Again, not my interest]
3 Finally, if looking for a lad to kiss, suck and bend over so he can be f***ed, I suspect it's much more difficult in Vietnam than Thailand.
I might be wrong on these points, but clarifying expectations can be important. People like me wanting a bottom lad (#3) might find it more difficult.
For example, I recall reading glowing praise of Moroccan lads by one member on another forum (now closed). Apparently, there were loads of them, all willing & available. When I started asking questions, he eventually admitted he was paying for the privilege of him sucking them off. Now, if that's what HE wants to do, it's fine. However, knowing this is quite an important detail, since I have zero interest in ever meeting lads for that purpose & it may be the same for some other members here.
As a further example, when visiting Romania, there were no end of lads willing to act as tops. If I'm the top, requiring a lad to kiss, suck and bottom, the field of willing bottoms narrows down to almost nothing.