The "hanging" method for fixing probably won't do anything for the guitar unless the instrument is very heavy. The pull of the strings, which is presently helping to hold the twist, has to be defeated. Reverse pressure is necessary to straighten a twist, and there are several methods on Youtube.
Severity of the twist is a concern. I have an old Epiphone with a twisted neck that I practice on. The twist just isn't that bad, and doesn't (yet) need fixing.
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