Let it go out of scope.

Unless it has circular references, or involves some sort of XS component that doesn't malloc() (whatever the XS function to return memory back to Perl's pool) properly, it should be reclaimed by the internal garbage collection schemes correctly.

I saw exactly what you described, though, in that every ten seconds it would eat up another small chunk of my memory. If I could think of a good object to use that didn't have XS components, I'd try that demo over.