I've tried everything with mine.  For a while I thought I had stopped the aggression.  It was only a pause.  He went back to the random attacks but they're pretty much limited to 10%-15% of our encounters and more upsetting than painful.  
I can't put him down.  I did his father and I still hate myself for it so I can't do it again.  What I do do to live with him is:
  
1) Keep long, strong sticks around the chicken yard in various places if I have to hold him off.  
2) Keep a putter at the gate to the yard.  If I am going in to do some business that's gonna take some time, I have the putter in my hand.  It has a long reach and a heavy head down where he might threaten.  
3)  Use the putter to herd him into the enclosed run if I want to work in the yard and into the yard if I want to work in the run.  
4) I've found that if I go directly at him he's gonna start raising his hackle feathers and prepare for an attack.  If I approach him from behind or the side he's going to move along to avoid the putter.  
5)  If he attacks, I don't back down.  I have to make the point that I'm going to best him every time.
6)  Keep him in sight all the time but if I have to turn my back on him, I still point the putter in his direction and wave it behind me.
Most of all, I wouldn't go near him not wearing long pants.  He's never gone at me higher than my knees.