Search by order total

Is there a way to search all my orders by order total (the _order_total meta field)? Either built-in, by plugin or by code.

I’ve written some code myself:

add_action('pre_get_posts', 'search_by_amount', 100, 1);

function search_by_amount($query)
{
    global $pagenow, $post_type;

    if (!is_admin()) {
        return;
    }

    if ($pagenow !== 'edit.php') {
        return;
    }

    if (
        $post_type == 'shop_order'
        || (is_array($query->query_vars['post_type']) && in_array('shop_order', $query->query_vars['post_type']))
        || $query->query_vars['post_type'] == 'shop_order'
    ) {

        $s = $_GET['s'];

        // Check if search term can be a float
        if ($s == (string)(float)$s) {
            $query->query_vars['meta_query'][] = array(
                'key'     => '_order_total',
                'value'   => floatval($s),
                'compare' => '=',
                'type'    => 'NUMERIC'
            );
        }
    }
}

Unfortunately, this doesn’t seem to work. I’ve tried different meta queries, but whenever I search for a numeric value, I don’t get a single result.

Does anyone know if/how this can be achieved?