Well, that statement is WRONG for a couple reasons:
Chocolate tastes great!
"Chocolate Tastes Yucky or bad" is not a statement I would use during a hypnosis session
Many people come to me with the request that they eliminate sugar or sweets, and I can definitely help with that. The statement that "chocolate tastes yucky" is an aversion technique used by some therapists; however, I get great results by emphasizing the positive.
Instead of planting suggestions / ideas into a person's subconscious mind that sweets are something NEGATIVE, I plant suggestions that a person has a powerful mind that appreciates everything that is GOOD for the person, and that mind is so strong and discerning, that it acts as an advocate in helping the person make desirable, healthy choices with food and portions.
Sometimes I use suggestions for a "super power" of the mind to be super sensitive to the smell of sugar to make it easier to pass on foods / sweets that the client wants to avoid. This is all in alignment with the client's desire for something positive and the greater, long-term good that can come from making healthy choices.
This is pretty easy to do, and my clients like this technique. Check out my testimonials for a great example!
Now, if we're talking about liver and onions, I won't deny that tastes yucky . . . but that's another topic!