I'd just pop it off, spray some sanitizer on in (star-san, iodophore) whatever you use and leave it be.. as long as it wasn't filthy to start with you should be fine.
So far since I'm fairly new to brewing beer I've only used cambden tablets and my beers and wines have been fine isn't here something i should use that is better? I'd hate to screw up a good brew due to poor care by my own part
in all honesty, i would of just left it alone since it doesnt make contact with the beer.. then sanitize the bung hole before you stick your racking cane in..