Render custom textfield that uses wysiwyg

I have some sample code here. basically i altered a block and added a textarea with wysiwyg. that works and is ok. the problem is how do i render wysiwyg created text, so that all filters like media, token are processed?
$html_text['content']['custom_html_text']['#theme'] = 'item_list'; is just an example. is there a theming function i must use here to get this proecessed?

/*
 * hook_form_alter
 *
 */

function example_form_alter(&$form, &$form_state, $form_id) {
  $foo = 1;

  if ($form_id == 'facetapi_facet_display_form') {

    //we need an id to save the textvalue
    $id = $form['#facetapi']['facet']['field'];
    //add custom html textarea
    $form['html_text'] = array(
      '#title' => t('Your custom HTML'),
      '#type' => 'text_format',
      '#description' => t('Custom HTML that will be displayed above the facet'),
      '#format' => 'full_html',
      '#rows' => 50,
      '#default_value' => variable_get("html_text_" . $id . "value", 'foo')

    );
    $form['#submit'][] = 'example_form_submit';
  }
}

function example_form_submit($form, &$form_state) {

  $id = $form['#facetapi']['facet']['field'];
  $html_text = $form_state['values']['html_text']['value'];
  variable_set("html_text_" . $id . "value", $html_text);
}


/*
 * hook_block_view_alter()
 */

function example_block_view_alter(&$data, $block) {

  if ($block->module == 'facetapi') {
    //get custom text
    $custom_text = $data['content']['#settings']->settings['html_text']['value'];

    if (!empty($custom_text)) {
      $html_text['content']['custom_html_text']['#theme'] = 'item_list';
      $html_text['content']['custom_html_text']['#items'][]['data'] = $custom_text;
      $html_text['custom_html_text']['#attributes']['class'][0] = 'custom_facetapi_text';

//      $data['content']['custom_html_text']['#theme'] = 'item_list';
//      $data['content']['custom_html_text']['#items'][]['data'] = $custom_text;
//      $data['content']['custom_html_text']['#attributes']['class'][0] = 'custom_facetapi_text';

      //we can put the text at the top
      $data['content'] = array_merge($html_text, $data['content']);

    }


  }