How long are you usually in SP? For most people, SP is very quick, lasting only a minute or two. It's transitory. For others (mostly beginning WILDers), it occurs slowly and gradually (because it is induced) or not at all (self-suggested sleep paralysis).

Wait until your thoughts try to randomize. Try visualization. Think of an object, like a book. Start with appearance. Size, color, age, thickness, title, position. Then think about the other senses. Feel the texture of the cover and pages, the weight of the tome, the sharpness of the corners. Smell the ink and paper, listen to the flapping of the paper pages. Then look around to see where the book is. Your mind won't leave you hanging, and will produce a shelf edge, a desk, a table, a floor, etc. as soon as you wonder. Continue immersing the senses into this new object, until you come across another object. Eventually, you'll imagine up an entire room.

I think you get the primary purpose of the exercise, but there is a dual purpose: to take your mind off your real body. People always focus on the body. "Am I in sleep paralysis yet?" No. You have to entertain the mind with other things. If, when counting breaths (or whatever), you can't stop thinking about sleep paralysis sensations, try visualization methods.