Someone wrote various [internal, [internalitems, and [internalmobiles scripts to clean up stray internal items, although those scripts and item leaks in general are fairly infrequent now. Still, buggy code can leak a whole lot of stuff onto the internal map. (My cooking package was doing that, fixed the bug but have yet to release a new version. Heh. =)
There's some built-in code that will remove objects it deems 'inaccessable'.
There's some built-in code that will remove objects it deems 'inaccessable'.