Given that leaks are often an indication that there a foible (bug?) in the code maybe a better thing would be to track down and fix the leak?

Tools such as Devel::Size, Devel::Leak and Devel::DumpSizes will help. Note that if you want to use Devel::Leak with recent versions of Perl apply the patch at rt://22587 (thanks lima1). The discussion in Tracking down memory leaks may be of some help.

On a different topic: Your C is showing! The Perlish way to iterate over a range is:

for my $index (1 .. 500) {
}
[download]

which is shorter, clearer and more maintainable.