When you think about it, the carboy is just a big bottle. As long as you can seal it well, it can be safely stored for many years. The key is getting it to seal at the opening.
Jamming in an oversized piece of bark provides a proven seal in a bottle, you just need to find a solid bung that will do the same, if you want to age in a carboy.
Jamming in an oversized piece of bark provides a proven seal in a bottle, you just need to find a solid bung that will do the same, if you want to age in a carboy.