Ferguson and Allan McGregor were banned from representing Scotland ever again for their behaviour while on international duty against Holland and Iceland last season.
The pair indulged in an early-hours drinking session at the team hotel in the wake of March's World Cup qualifying defeat in Amsterdam.
They then reacted to being dropped to the bench against Iceland days later by flicking V-signs at photographers.
Midfielder Ferguson, who left Rangers for Birmingham this summer, said in the Evening Times: "I was totally in the wrong with what happened at the hotel. I would never sit for a second and try to dress that up in any way or try to make a case for what went on that night with the drinking.
"If I could go back and change things, I would - of course I would. I should have gone to bed, and I should never have made the V-signs - when I see the pictures of that I feel so stupid. I looked like a daft idiot and I should have known better. But it was an error, a bad call.
"I let myself down, my family down, my country down and I let Walter Smith, Rangers and the supporters down. That's something I'll need to live with and it does still hurt me. But I made a mistake and people do that - I am a human being, not a robot and I made a costly mistake.
"The thing that rankles with me now is the way the SFA handled the entire situation - for me it was a joke. I had played for Scotland 45 times, I had captained my country for years - and they sent a fax to Murray Park saying that I would never play for my country again. It was just the same statement they put out, that was it!
"That just astonished me. The machine starts to ring, and in comes a fax from Hampden for my attention telling me that I would no longer be picked, and neither would Allan.
"The people in the room just looked at each other in total disbelief - is that how something like that should be handled?
"No-one has ever spoken to me from the Scotland set-up. Not the manager, the chief executive, a PR guy, anyone. I was driving back into Murray Park after being sent home for a few hours and I heard on the radio that the SFA were going to ban me for life.
"I was in such a whirl that I wasn't taking anything in - then a fax arrives and that was it over. no phone call, no anything.
That, for me, sums the SFA up. They don't know how to handle anything properly."