I told mine many fantasies, including pretty surreal, fictional, even dark and violent ones. I often emailed them because I am much better at writing fictional things than verbally expressing them in the moment, but we discussed many in sessions afterward. They were fodder for interesting conversations and the Ts were usually interested. One of them liked to associate the fantasies with books, movies and other forms of art that my stories reminded him of and I often checked those out on my own when I did not know them already. Those exercises were usually really stimulating and fun although not very useful because they never solved any of my actual issues. More the opposite - one of my main issue was drinking and I often emailed those fantasies drunk, because that's when I tended to get the most bizarre ones... but rarely shared that I was drinking during. Or procrastination - I often dreamed and wrote up those fantasies instead of doing something I really had to do. But I think it can be very useful exploration in the right context. It's not necessarily nonsense IMO.