This is a method I have never used. I have no experience with it It sounds like it would work. Other than that,you are on your own.
I must give Mr Guffey credit for suggesting it some time ago.
Mr Guffey mentioned using a carbon arc electrode as a contact to apply electrical current to the head of the screw. Its about amperage ,resistance,and heat. Its NOT about an arc.
An arc will crater the screw head. Switching must occur off the screw head.
An arc welder or 12 volt auto battery might be the power source.
That's all I can tell you.I never developed a technique .
More conventional: Set the gun up in a drill press or mill,spindle centered over the screw. Use a high quality,proper fitting power screwdriver bit in the chuck.
You don't turn the machine on .Put it in neutral or loosen the belt.
Use the spindle to simply hold the screwdriver bit square and centered,with some pressure down into the slot. Manually turn the spindle.
Another method of heating a part that can be messy and dangerous is dunking it in hot peanut or other high smoke point cooking oil,heated to smoke point,approaching 400 f.
Most Loctite will break at that temp. 400 deg f will not harm bluing or heat treat. Its an even heat,edges or thin sections won't overheat.