Have never tried slow roastiing corned beef, but thinking it might take even longer than in a crock pot or on stove top? Would try it if I had a cooking source where I could just get it started and walk away... for SEVERAL hours, I'm thinking!
Reluctantly admit to trying to cook corned beef in MICROWAVE one time!?! WHAT was I thinking?? I guess technically it was done in about 10 minutes, but HARD as a bowling ball... ended up finishing it (to fork tender) iin big pot the way I should have from beginning.
Have cooked a CB till almost there, then transferred to stove top smoker with a pastrami-ish rub... made great sandwiches.
Not corned beef but another SLOW cooked thing... ribs. Last summer, took 2 nice racks of baby backs along on a road trip froom NJ to WV... with recipe from Good Eats... something like "whose your baby back". Had a fairly spicy rub... salt, brown sugar, and messa spices... rubbed on and wrapped in a few layers of foil to sit over-night. Then into oven, with a liquid mix added for 2-3 hours at a pretty ow temp... maybe 275-300. Last step was a quick sizzle on grill... maybe half an hour... marinate from foil pouch cooked down till a "glaze". They were GREAT.
I did try that a few years back, because I'd had some at a bar that was done that way and it was delicious. Mine came out tasty but tough, but I think it would be worth some more experimenting. I don't remember how long I roasted it, but I do remember that I looked up roasting time for brisket (not corned) in Joy of Cooking and followed that.