David, plenty of plus gas, tighten the bolt first, then slacken.
As soon as the bolt starts moving, change from 1/2" to 3/8" drive sockets, this gives you much better feel for what is happening.
The trick is, if the bolt becomes tight while being slackened, stop and reverse the ratchet and tighten it again, and plenty of penetrating oil squirted on the end of the thread.
Working the bolt in this way reduces exponentially the likelihood of the captive nut bursting out of it's cage, if you attempt to wind out the bolt in one go, it will almost always end in tears.
This is more likely to help you than your tool, which would be almost impossible to position to support the cage of the captive, and even if positioned perfectly, the arm of the tool is 90 degrees away from being useful in preventing any rotation
Brian
