Erotic massage studios in Cologne are of the New Age sort. Think more of that sexual tantric therapy stuff than hand job assembly lines. Shiva Tantra Massage (https://www.tantra-shiva.de/) at Greesbergstraße 5 and Ruhepunkt (https://www.ruhepunkt-koeln.de/) at Mühlenstraße 8, should give you an idea of what to expect.
Most massage parlours in Cologne have tantric and comparable sensual massages in their service list, in case you are looking for more hard-core massage sessions you better visit one of the many brothels in the city
I would have anything of Barry White or Marvin Gaye’s Sexual Healing playing on loop if I would own a sensual massage salon in Cologne. You can get serviced in certain studios offering erotische Massage in Köln, but most people would just go to a brothel instead. Prices are comparable as you need to pay around €150 for an hour of “therapy”.
