I don't think you should expect to be sucking so many young guys there--they are there, yes, but more easy to meet are the older guys, in late 20s to 40s, who are there to get sucked.
Just buy a ticket at the window outside the building on the left (40 baht--is that right?), go in the door, give the ticket to the ticket taker. Go inside, and you'll realize it's SUPER dark. I usually wait about 5-10 minutes at the door so my eyes get adjusted to the darkness. Then go up the stairs from where the entrance is (there are stairs an both sides and up the middle).
Guys who want to get sucked are often sitting in the 2nd or 3rd-5th seat near an aisle, and might be rubbing their dick or have it out. If they look at you and keep rubbing, go for it. If they're just looking straight ahead, sit down next to them and slowly reach over to their crotch... if they don't get up and leave, they want a bj...
I'm an in-shape guy, clean, and wear kind of muscle clothes to the theater... I recommend you dress lightly, since it can get hot in there, especially since I'm working so hard!
As for how much success to expect: I usually get 3-8 loads from reasonably young/good-looking guys. I have found, though, that if it's not happening, I will suck an older guy in his 40s or 50s and then the younger ones will see... and want some from me too. Who knows if it works, but it seems to work for me.
I've seen a couple older farangs there, one who wears a hooded sweatshirt and sunglasses (!) who seems to have much less success than I do. But he must be enjoying himself, since I've seen him there at least 3x! Younger and/or in-shape and not "weird" looking farangs seem to do well, which of course is no surprise.
Has anyone played at the Freeman Dark Room since it re-opened?? I haven't heard one word about it, and it was always a nice place to go after arriving on late-night flights from the US for a snack before bedtime......thanks!