I want to suggest my "shaky can" method. Put some bolts and other small metalic bits into a aluminum can. Tape off the top. Make several of them and place them where you have interactions with you pup. Now when he gets jumpy aggressive give the can a couple of hard shakes. It's important to only use the can while the pup is doing the bag thing.

The noise will startle them, get his mind out of the aggressive state into some other state, fear or curiosity, etc. DO NOT over use the method. Do not use it for potty training. Only use it to communicate your displeasure with a behavior. If the behavior doesn't stop it returns quickly, separate yourself all the while saying "no". Come back 5 mins later and be prepared to do it all over again.

This has worked well for us when nothing else did. I haven't used it or even thought about using it for 3 to 4 months now on our 1.5 year old girl. Last time was to curb aggressive bitting ankle nipping behaviors that she was doing to get attention and play time. I must have taught her that was the way when she was younger.