[trevius]

This seems to work to only delete the corpse if it is empty:

my $deadnpc = $entity_list->GetCorpseByName("Tiny_Albino_Rat's corpse423");

  if ($deadnpc->IsEmpty()) {
    my $delete_corpse = $deadnpc->CastToCorpse();
    $delete_corpse->SetDecayTimer(1); }

The only thing left is to figure out how to select corpses without having to provide an exact name or entity ID number.