Blaster,

I'm sure AC SMAW operations were mentioned in Henery's links...   This is what I typically do when welding fixtures begin to cause arc blow.

However I have some high current SAW fixtures that had become so magnitized they cold literally hold a half pound plate.   AC operations did not dmag in a reasonable time...

I appoached Lincoln on this and one of their engineers suggested the same SMAW AC set-up... Largest possible electrode and current setting the power supply could handle... But instead of just doing welding operations, he told me to simply dead short the electrode into the offending workpiece and let it stay that way until the electrode became unstable or the internal breaker in the power supply kicked...  I did this several times while moving the work clamp to each point on the fixture...   It worked.

Edit:
I have never seen this approach published openly...  You need a SMAW power supply with a pretty robust duty cycle as you might imagine.