Block Formidable Forms entries

functions.php

<?php
// Add this to theme functions.php and rebuild the index to remove Formidable Forms entries from index
add_filter( 'relevanssi_indexing_restriction', 'rlv_no_formidable' );
function rlv_no_formidable( $restriction ) {
	global $wpdb;
	$restriction['mysql']  .= " AND post.ID NOT IN (SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attached_file' AND meta_value LIKE 'formidable%' ) ";
	$restriction['reason'] .= ' No Formidable Forms entries';
	return $restriction;
}