Here’s my opinion on the ethics of communication.
Ethical communication is different for every person. It depends on the boundaries, preferences, issues, triggers, and susceptibility of each person involved. In a one-on-one situation, you can use your best judgment of how your communication will affect that person, and be sure to avoid harm to the best of your knowledge and ability. You can talk about it explicitly.
When constructing a workshop, it’s similar. You may not be able to speak to each potential attendee individually, but what you can do is provide full disclosure of exactly what will and will not happen during the workshop. You can be open and honest about what methods of communication, learning, and interaction will be offered at the workshop. And then you can trust your attendees to exercise their best judgment and be big boys and girls. As long as we’re open and honest about how we communicate, teach, and interact, we can trust others to determine what is beneficial for them.