Erotic massage in Dubrovnik is huge, just not in the salon department. There is a handful of massage parlors in Dubrovnik, but they’re just not very erotic. I heard rumors that Thai massage is outstanding around these parts. Touch of Thai (http://touchofthai.eu/) at Obala Stjepana Radića 2 is a well-known spot. Don’t think you’re getting a handjob just because it’s a Thai studio. Icona (http://www.iconathaispa.com/) at Ul. od Sigurate 4, is more or less the same thing.
You could try in one of the beach clubs around Dubrovnik such as Coral (https://www.coral-beach-club.com/) since they often have a spa area. Classifieds are the way to go if you’re dead-set on that happy ending. Take a look at Ljubavni Oglasnik (https://ljubavni-oglasnik.net/). I can’t really give a proper price with these; it seems those girls just throw random numbers at you. I personally consider anything above €150 a rip-off anyway.