I answered as well.
The next day, I did the same again with a different group of people, announcing "Flash-mob scrum" as we started.
Today I rounded up a couple of people from previous days and we "flash-mob scrummed" by two new people. I'm hoping it might just work.
This was done in a spirit of TCC, larking about, but based on previous practice, which is vital for TCC. The team seem to be talking to each other bit more too.