The following script deletes all images, except those that are in use by WooCommerce products.

function delete_unused_images() {
    // Get all product IDs
    $product_ids = wc_get_products(array('limit' => -1, 'return' => 'ids'));

    // Get all attachment IDs
    $attachments = get_posts(array(
        'post_type' => 'attachment',
        'numberposts' => -1,
        'post_status' => 'inherit',
    ));

    // Create an array to hold IDs of product images
    $product_image_ids = array();

    // Loop through each product to get their featured images
    foreach ($product_ids as $product_id) {
        $product_image_ids[] = get_post_thumbnail_id($product_id);
    }

    // Loop through each attachment and delete if not a product image
    foreach ($attachments as $attachment) {
        if (!in_array($attachment->ID, $product_image_ids)) {
            wp_delete_attachment($attachment->ID, true);
        }
    }
}

// Hook the function to an action, e.g., admin_init
add_action('admin_init', 'delete_unused_images');
Code language: PHP (php)

Source: Einar