as mentioned above, Club of Eden is not bad, but it is still a tourist destination. As in they serve mostly non-Thai's
If you want a local bath+sex you can go to J-One (Chaopraya one). It is next to Bangkok Hospital. The last time I was there the girls were pretty hot. It starts with a nice bath where the girl washes every part of your body, then its the full nude body slide/massage. The girl I was with gave me a nice bbbj and ACG. I asked for her number before I left and we hung out later that night for more fun at my hotel(she didn't let the manager know so I didn't pay the overnight fee)
Anyways, J-One is becoming more famous with tourists now, so now I head down the same road to J-Two
It is more for locals cause I was the only non-Thai checking out the girls behind the fishbowl, and by the way the girls can't speak ANY english. I was trying to ask my girl her name, and she had a hard time understanding. Then I asked her to give me a bj and she had a hard time understanding that too, so I'm just like fuck it and bang the shit out of her.
By the way, both J-One and J-Two are HUGE, you can't miss them. They are like the size of a hotel.
Finally, if you are taking a taxi, have the taxi driver drop you off a block before the bath complex and walk in yourself, otherwise they would think the driver took you here and charge you a bit more to pay the taxi driver a bonus.