I've worked with people who have spent 28 days inside and I've seen documentaries on it - to be honest, the documentaries don't do it justice in terms of how soul-destroying it must be. I think it's impssible for a civilian to appreciate what military discipline can really be like.

Just being stripped of his rank will be pretty bad - I'm guessing it's like the Army and he'll ahve gone in at that rank being Professionally Qualified so won't be used to even being a lower officer rank. (Can't remember RAF ranks, but I remember that Flt.Lt. is like an Army Captain, you get a fair bit of respect if no real actual command responsibility when you've gone in as a PQO)