popsu-d7/sites/all/modules/node_clone/clone.install

<?php

/**
 * Implementation of hook_uninstall.
 */
function clone_uninstall() {
  variable_del('clone_method');
  variable_del('clone_omitted');
  variable_del('clone_nodes_without_confirm');
  variable_del('clone_use_node_type_name');
  variable_del('clone_menu_links');
  $types = node_type_get_names();
  foreach ($types as $type => $name) {
    variable_del('clone_reset_'. $type);
  }
}