Sand. Thow some sand in there with the cleaner and shake well. Also
letting the carboy sit for a day full of bleach water might do it.

Bob


Steve Sauchinitz wrote:
> I have a few carboys that over the years have some lime or film residue
> inside. Clorox or CLR won't remove it. Does anyone know what I could try to
> clean these up with?
>
>
> Steve