some years ago i used a epoxy type repair where you put it on the threads screwed it in then unscrewed the fitting and waited for it to setup,i used it on a stripped ford brake caliper,i cant remember the exact name ,but it was something like thread renew,etc,etc
it worked great seems like you had to put something on the good threads first so they would release after it was screwed it before it cured,its been a few yrs back ,my memory is pretty spotty in my old age