So first of all you need to isolate the offenders. As I talked about above this needs to be away from the players with a clear pathway to the changing rooms. I am happy with the slowing down here.Ok from a learning point of view. Say that you are going to send off red 2 and 7, blue 11. What is an appropriate way?
Flashing the cards or take names and slow the process down?
7 seemed the start it but 2 was worst offender imho (stamp) does he go 1st?
In terms of order I'd deal with one teams reds then the others. This would allow you to reposition yourself if needs be between sanctioning teams to keep the clear path way.
I wouldn't recommend flashing cards here. Everything should be slowly as possible to leave as much time between restart. There has been a major flash point followed by several dismissals. We need everyone calm before we restart. Easiest way to do that is to slow things down