Nothing was more fun to do, while remaining serious at it, than the dunker at NAS pensacola when going thru training, then HEEDS training as well (HEEDS - small breathign apparatus, and if anyone interested, you can get them from most scuba stores, known as pony bottles, will give you 5-7 min of air ...)
The biggest thing IMO if briefing pax is the same as for flight crew: Know the thing IS going to roll over if it has the room, and to have a reference point selected, grab it and hold onto it. Remain calm.
Your listing of the exit drill is very nice, I prefer to grab the release or a point next to and the harness (at least when I went through it).
We would do the dunker 4 times:
2 rides where everyone goes out their own exit/window (day/night).
2 rides are where everyone must coordinate an exit through a common door. (day/night).
I had the "worst" spot for the night common simulation, I was across the aisle furthest from the common door, but we (8 positions, 6 in "back" pilot and copilot in "front") wer given a minute to discuss what we wanted to do as a brief, then we were dunked.
It is an eye opener, and anyone who is going to fly offshore should at least attempt to eother have a good briefing on it, or go through it if possible.