Throttle Shaft Leakage on Carburetors - Briggs, Kohler, etc

Don't matter what brand engine, I usually will replace the carb when a Throttle Shaft leak is detected and adjusting idle screw in and any other adjustments doesn't fix the Hunting or Surging.  However, I'd like to get a discussion going on any successes techs have had fixing these throttle shaft leaks. It would be great to be able to get some of these carbs working properly instead of replacing. Any suggestions on fixing these leaks that cause Hunting and Surging (assuming the governor has been static set its not a governor or linkage problem or and intake manifold leak)?