To answer the inquiring lesbian friend...
On the surface, the bathhouse is basically a spa. Naked men in towels, taking showers, using the steam, sauna, jacuzzi, and gym facilities. There is often a dark back room with a glory hole maze involved.
Through that, you find ways to make contact with guys. Guys can be choosy in this environment as they need. Men of all sorts go to the bathhouse, hot ones and lesser so. You go and try to hook up with guys you think are hot, don't take it personally if you are rejected, and don't feel bad about rejecting an advance you don't like.
People mostly go by themselves. It's sexier than going with a group of your buddies, because let's face it: four queens descending on a bathhouse is a dick wilter, because there is going to be all manner of chatter and whisper and fear of doing something sexual in front of your friends.
Often times, couples will go there in order to spice up their sex lives a bit.
There are many screens showing porn. There is usually a DJ (sometimes a very good one). Sometimes it's just a CD player that may or may not be well monitored by staff.
You pay a membership fee to the Club (which gets you around the legality of 'public sex'...since you are paying for 'private membership'). Usually $12 for 6 months or something. Then you also pay a fee for use for the day. You can choose a room or a locker. Lockers are cheaper. If you get a room, then you can lay on the bed and hope for guys to come into your room. If you get a locker, you must walk around and look to get laid either in the facilities, or in someone's room.
The rooms are only big enough for a small platformed mattress and access thereto. There are sometimes TVs in the rooms playing porn.
Some bathhouses have big TV rooms playing porn. Others have a big open area where anything can happen...like a massive orgy. Orgies also happen in steam rooms (if everyone can handle the steam level for that long). Jacuzzis usually don't have sexy time - and that's often enforced by the staff.
I like to just go and relax in the jacuzzi first, unwind a bit, and see who is wandering around. Then i shower up and look around some more. More often than not, I have a great time with hot guys.