I used this recently with a group of about 50 diverse undergraduate students and it worked really well in person, but I think it could also work online as long as you have the capacity to put learners into small groups for discussion. One thing I noticed about drawing out discussion in the large group was how important it was for me as a facilitator to be vulnerable and model the kinds of contributions I wanted them to make to the dialogue. After the first question was met with crickets, each time I asked them to reflect or generate example stories, I provided one from my own experiences to jumpstart discussion. That technique worked well and we got some really insightful comments and examples from the group despite the large group size.