Is it helpful to talk about non-duality with others who share an interest in this subject?
Yes... and No. Let me explain.
In the early stages of our investigation, we tend to talk a lot about non-duality and how we can realize our true nature. We have lots of questions and want answers. The mind is very engaged and believes it can learn this new thing called non-duality.
We may attend meetings with non-duality teachers where non-duality is discussed and questions posed by the attendees are answered. This type of discussion is usually quite helpful if the teacher is self-realized. In these instances, much more than words are communicated and you can feel it.
As for talks between students of non-duality, I think this is less helpful than most people think. Such discussions are very active at the level of the mind. After a discussion with friends (including those who are well versed in non-duality), we may think that we have gained momentary clarity on a particular issue. However, it isn't long before the mind seeks answers to other questions, and may even re-visit the issue we thought had just been resolved.
I've found that eventually talking gives way to silence and contemplation. I'm not saying that talking is the enemy or that we should never talk about non-duality. I'm still drawn to talk about non-duality from time to time. However, it is for the love of discussing the topic and NOT because I think the talking is going to explain anything new to me.
If you like to gather online or in person for non-duality discussion groups, go right ahead. That is just what you need right now. It can be a lot of fun, and there is great comfort in finding others who are interested in this subject. As we all know, non-duality isn't exactly the most popular topic on the planet, and most people think you're crazy when you speak about your new view of reality.
For those whose goal is self-realization, I think the talking eventually slows down. You will come to a point where the mind's questions no longer entice you. You KNOW the mind can't provide you with answers. Silence will be of more interest, and you may find yourself contemplating the nature of your own experience.
By the way, not everybody who attends meetings or becomes interested in non-duality is earnestly seeking self-realization. There is absolutely nothing wrong with that. Some people enjoy being part of the community and discussing this subject.
Follow your heart on this issue. If self-realization is your goal, consider whether talking about non-duality is really helping you -- or if it is keeping you in an endless mind loop. You'll find the balance of talking and silence that is right for you.