Remove plugin asssets on all other pages than needed

functions.php

<?php
// Remove plugin asssets on all other pages than needed
add_action( 'wp_print_scripts', 'my_deregister_javascript', 100 );
function my_deregister_javascript(){
    if(!is_page(408)){
        wp_deregister_script('contact-form-7');
    }
}

add_action( 'wp_print_styles', 'my_deregister_styles', 100 );
function my_deregister_styles(){
    if(!is_page(408)){
        wp_deregister_style('contact-form-7');
    }
}