I can't find the old thread so I forget who gave me these instructions - but whoever it was, thank you - it works!
I used an off the shelf raw Mosey's corned beef, smoked it for 8 hours, covered it with cracked black pepper, wrapped it up in plastic wrap and then in foil, and threw it in the back of the fridge and left it for 2 weeks.
We took it out today - steamed it whole, and sliced it up. Delicious! And really a pastrami, by texture and taste, not just a smoked corned beef - which is what I had the last time I smoked a corned beef and didn't let it go through the peppered, wrapped treatment.
Now I have to start fooling around with this. I'll try brining my own brisket, rather than using a pre-brined (God knows with what) one. But the basic technique really is quite easy, and definitely produces a tasty product.