The concept of sexual reconditioning can be to either create a safe and pleasurable connection to the act to reinforce the good parts of it, or to create a negative association with an unwanted behavior.
So, if the efforts are to create a positive connection to sexual release, it might focus on pairing safe and comfortable behaviors with the self-reinforcement of pleasure. One way to do that might be to direct your partner to do what feels safe and comfortable to you and avoid making any connections with unwanted behaviors, such as causing pain. This may be difficult to do after many years of conditioning to the unwanted behaviors to achieve orgasm. It may take a lot of exploration to find more acceptable behaviors that have the potential to create the new pathways to orgasm.
The negative associations, when I'm dealing with people having fantasies they want to get rid of, is to couple the unwanted fantasies with unwanted results via negative imagary. For example, if a person was trying to get rid of using harmful masturbation activities, when the thoughts that might provide some arousal to act on them, flood them with imagining doing that behavior in front of your parents. Assuming you wouldn't get more aroused by doing the behavior in front of an audience, it should help break the arousal conditioning you have previously reinforced.
It is a difficult and sometimes long journey to change the associations but recognize that you probably have been reinforcing the unwanted connections for many years and it will take some time to change it. If your therapist is experienced in this are, s/he can help you change. The use of noxious smells or electric shocks (generally a pretty extreme practice) is the behavioral expansion of the negative or embarrassing fantasies I described above.