Well, that's the main reason why I always prefer to stick with 本番店(shops where offer FS)
I had worked at several health shops however, I always worried about giving them Sumata; rubbing pussy against uncovered penis. It is standard practice at delivery health shops where don't offer FS. Now, I feel much better as I don't need to worry about gettting something by providing Sumata. Very few clients have asked for Sumata specifically.