You won’t see much erotic massage action in Muscat. There is an Asian parlor here and there, but those come and go. A massage in your hotel or apartment provided by a lady of an outcall massage service or independent escort offers the best options when you want a good rub and tug.
Try Muscat Massage (https://www.muscatmassages.com/) or Oman Girls (https://oman-girls.com/), known not only for escorts but also for their sensual massage services. Have around $150 plus $50 tip prepared.