She has him hypnotise himself.

"Richard my love. You have a hypnotic fetish and as such will seek out all books and information on hypnosis, especially erotic and self-hypnosis. Being in a trance makes you horny and submissive, it also makes you think of me and how I must be obeyed. Each night when you get home to masturbate to me and before bed you will hypnotize yourself, once you know how, and enforce the lessons you have learned from me. As well as any new ones.

"Understand, my pet?" asked Danielle as she knew getting him to hypnotize himself would enhance her hold on him and make less work on her to do it.

"Yesssss, my Goddesssssss!" said Richard as he smiled and moaned out the answer in a blissed out state.

She thought, what to do next?

Hypnotic suggestion, to make him react to my words. Like orgasm or changing his mind to my thinking. Develop sexy persona for him to take once I mention the code word.

"Or I could do both, something else or all of the above. What game do I want to play now?" asked Danielle as she decided on the next lesson.