Explaining how to create Rule that accept arguments (user can enter any value) and adding VBO field in Views: The Power of Rules with Views Bulk Operations (and Commerce)
From Joren comment:
function modulename_form_views_form_test_view_page_alter(&$form, $form_state, $form_id) {
$form['#submit'][] = 'modulename_vbo_submit';
$form['select']['arg'] = array( '#type' => 'textfield', '#title' => t('Whatever') );
}
function modulename_vbo_submit(&$form, $form_state) {
$nids = $form_state['selection'];
foreach ($nids as $nid) {
$node = node_load($nid);
rules_invoke_component('rules_test', $node, $form_state['values']['arg']);
drupal_goto('test-view');
}
}