So many controversial stories about fish attractants. I like the theory that fish scents hide your odors so that you won't scare fish away. Pretty good theory to me and successfully tested it over time. I couldn't catch a trout this past winter until I figured me taking a shower and spraying cologne before leaving home was the possible cause of getting skunked. I started washing my hands with lemon-based dish soap to remove the cologne smell out of my fingers, and then touched some garlic scents to make sure I had no residue left. It worked. I caught so many trout after that.
To your question: I first start fishing without scents and see how it goes. Then I move to one if it's slow. I start with Hot Sauce (my favorite), then Uni Butter, and finally Pro-Cure Anchovies, Sardine, or Anice. It's funny how they might hit Sardine one day, literally hammering them, and the next they won't even touch it and go for Hot Sauce instead. I usually reload after I notice it's taking longer to hook a fish. Don't have a real count, don't really reload after a bite. If my bait is working, good. When the bite slows down, it's time to reload my bait.