WP YouTube Lyte stores data it fetched from YouTube’s API in WordPress’s add_post_meta, thus avoiding to have to contact YouTube for subsequent requests. You can clear the entire cache by ticking that option on Lyte’s settings-page, but maybe you want to only remove the cache for one specific post or even fix a problem with a stale cache-entry?

In that case, this little code-snippet (to be used in a plugin or in your child theme’s functions.php) might help:

if (is_admin()) {
    add_filter( 'is_protected_meta', 'lyte_unprotect_meta', 10, 3);
}

function lyte_unprotect_meta($protected, $meta_key, $meta_type) {
    if (strpos($meta_key,"_lyte_")===0){
        return false;
    } else {
        return $protected;
    }
}

This little filter tells WordPress not to consider post_meta with a key that starts with “_lyte_” as protected, rendering it visible in the “Custom Fields” box on the “Post Edit”-screen. If this is active you can just edit your post, going to “Custom Fields” and removing the entry (or change it’s value, if you’re a guncompressing, base64_decoding hard-ass like that);