This question is a bit more complex then it sounds at first. On Earth when getting a massage you lay on a table and gravity and friction holds you in place while the therapist pushes, pulls and kneads your body.
In Microgravity your body would tend to bounce, between the masseuse and the table. If you try and hold yourself in place it would fail the "relax" part of the massage experience. Straps might be used but unless they were fairly tight and several of them, would seem to not a be a solution to the bounce issue.
I considered a table with a light suction to hold the massage receiver in place, but was not sure if that would be viable solution. You would need to mimic the friction a 1G body on table without causing undue sheer force at any one body location.
This question focuses on the massage receiver, it is a given that the masseuse would need some way of anchoring themselves.