Berber,
You can visit a place called, Tarawadee Resort and Spa. You can look up their website address by going into
www.ilikemassage.com
My good friend from Canada named Mr. S______n, said Tarawadee Resort and Spa has excellent spa services and soapy massage. It's quite expensive but girls are very attractive and provide excellent service. The location is far from Rachada or Sukhumvit but big deal just hire a cab and go for it! They do provide ball massage and they will clean your rectum for an extra tip!
It's after cafe Biwa or past end of Petchiburi Road ....
Good Luck