About six months ago I kegged a batch of beer from a 6 gal glass carboy. The carboy was a mess inside and I didn't feel like cleaning it at the time. I filled it up with fresh water and put it in the corner of my garage. I pretty much forgot about it until last night when I tried to clean it. Apparently some funky stuff took place in the carboy over the summer. All the gunk came out and the glass looks perfectly clean, but there is a terrible sulfer smell that I can't get rid of. Anyone have any ideas on how to get that stink out? Thanks.