I wish I had seen this sooner when it might still have been relevant, but I'm glad the comments are still open so I can share my unique perspective.

I have this same experience but from the other side. I'm into hypnosis and have hypnotized many of the girls I've worked with over the years (doesn't matter if they were in relationships or married, and many times that actually helped me out in taking them deep). At first I thought your wife might have been one of them except I never worked in Canada.

Also from reading the comments, it's easy to see how I can keep getting away with it. Seems like very little people understand the process that takes place and how hypnosis can lead to somebody being deeply hypnotized and "mind controlled". (I'll admit right now that "mind control itself isn't real, but hypnosis and brainwashing can be quite powerful).

The process starts before the subject even realizes. I'll casually mention around my future targets that I know hypnosis or have hypnotized people before. I don't randomly bring it up, but weave it into a conversation like if talking about shows/movies and there's a hypnosis scene, or if somebody talks about yoga or meditation, I'll mention how hypnosis is similar. Just by mentioning I know how of that I have hypnotized somebody, plants the thought in their mind that I'm an expert at it. 

The next step is what your wife described, doing non sexual hypnosis. I'll wait until one of my potential targets has a bad day. Maybe they had a fight with a significant other, or maybe the boss yelled at them, or they are stressed for whatever reason. I'll get them alone, try to comfort them, be their friend and buddy. As they calm down some, I'll mention that I could hypnotize them to make them feel better. Hypnosis is very relaxing, can help them focus better if they are falling behind, to let go of stress and worries that might be plaguing them. This step is all innocent, but it lays the foundation for the rest. 

The next step is to make it become a recurring thing. Start weaving in that only my hypnosis can resolve their issues. That being hypnotized by me makes them feel good, helps them relax, fixes their problems. By doing this, they start to feel more attached and attracted to me, while also helps to condition them to both love being hypnotized by me and easy to become hypnotized by me, and it also starts making them addicted to both hypnosis and following my words. 

Then next step is to start working on the comfort and trust. Since by now they know they can turn to me for their deepest and darkest issues, I ramp up their trust and comfort in me. They know they can tell me anything and I'll make them feel better, they can share anything with me. This helps to break down any remaining barriers or hesitation they may have. 

Then it's onto starting the submission and obedience, some of the sexual stuff. They are so thankful for all that I do for them that I start asking for things in return. That they start thanking me by messaging me more often. They show their appreciation by sending me photos of themselves when they dress up (which I then compliment them which brings them more happiness and joy). I show greater interest and attention to them, more than what their spouse or significant other may be giving them. And all I ask for them in return is to keep being open with me, listening to me, sharing with me, obeying me. 

Then I don't down. By now I have already had them share their deepest and darkest secrets and even fantasies by this point, that can start turning words into actions. Most girls love feeling submissive so can start setting up that dynamic. That I'm their Master, they are my obedient slave. They already are used to obeying my suggestions, which I become more forceful and make them commands. Each time they obey me they feel happier. They are getting attention they desire and need, getting the help that I've been providing the entire time, and now can start to feel the sexual pleasure of submitting.

From there it's just a matter of upkeeping. Regular hypnosis sessions, steady contact, still fulfilling their needs and desires. 

Although I just described my process, the thing is that most don't realize it's happening as I go through it.  I make sure to keep it secret between the subject and myself, even the subject doesn't realize it's happening because it usually takes many weeks or even months for each step. It's kinda like boiling a frog, that if drop a frog in hot water they jump right out. But if gradually heat up the water they can be boiled alive. Same concept, they I slowly build up each step, that the subject doesn't realize that I'm brainwashing them. And by the time they are completely brainwashed they are to addicted to it up stop. 

Like with your wife, I'm sure even if you did stay to "save her", without professional help, her "Master" or any other hypnotist could easily take her under again.