use strict;
use warnings;
use Path::Iterator::Rule;
use MCE;

my $rule = Path::Iterator::Rule->new;
# Add constraints to the rule here

my $root = '/some/path';
my $iter = $rule->iter($root, { depthfirst => 1 });
my @list;

while ( my $file = $iter->() ) {
    push @list, $file;
}

my $chunk_size = 100; # whatever makes sense for you
MCE->new( user_func => \&task, max_workers => 10, chunk_size => $chunk_size );
MCE->process( \@list );
MCE->shutdown;

exit 0;

sub task {
    my $mce  = shift; # not used in this case
    my $file = shift;
    unlink($file) if -f $file;
    rmdir($file) if -d $file;
}

__END__