Since no one else has replied, I'll bite. I've heard conflicting info about this for some time, and since it doesn't really apply to me or anyone I know (all of us have proper papers), I am at a loss for the emperical evidence that you --justifiably-- request.

Anyway, based on my research, I've come across two different scenarios:

SCENARIO 1
-persons traveling in sanctioned groups of 6 or more people may be issued visas on arrival

SCENARIO 2
-persons traveling in sanctioned groups of 6 or more people do not require visas (including visas on arrival) at all, AND
-persons from applicable countries are permitted to apply for visas on arrival

My gut tells me that "scenario 2" probably (with 80% certainty) reflects the true situation... so you'd be fine.

But, I would certainly ask some of the travel agencies in HK for their opinions because: 1) I don't know of any FTers that have attempted it; and 2) speaking from 2 experiences, boarding a plane --or worse-- arriving in country without the required documents is a real drag.