Its a struggle without being able to lock the engine (clutch holding tool etc) I just managed to get mine undone with the method you mention but I had to get a lot of weight on the back wheel to stop it spinning. Its useless to try it on the paddock stand with the locking bar as all that happens is the back wheel turns and takes the stand with it!
I managed to do it on the Multi after a while but my 996r was a different matter. I broke 2 Halfords long breaker bars before giving up and taking it down to the local bike shop, even with the application of heat they couldnt get it undone! Tried 2 more garages who all failed until I took it to a mates place, He made a metal shield to protect the o rings of the chain and then heated the nut right up, still took a few attempts before it finally cracked loose.
Let me know if youre still struggling and I will nip round and give you a hand, I now also own the most unbreakable of breaker bars (Stahlwille) expensive but top quality.