Remove product after an order has been placed in WooCommerce

I’m using the most recent versions of WordPress and WooCommerce.

I’m aware this might seem weird out of context, but I wanna add a hook to my functions.php that removes a certain product by ID from an order after the order has been placed.

Here is what I am working with so far:

add_action('woocommerce_new_order', 'custom_process_order', 10, 1);
function custom_process_order($order_id) {
    $order = new WC_Order( $order_id );
    $items = $order->get_items();
    foreach ($items as $item) {
        if ($item->get_id()==10766) {
          $order->remove_item( $item->get_id() );
        }
    }
    return $order_id;
}

I am trying to remove the product with the ID 10766 from the order if said product is part of the order. I took this from a different, older post here so the code itself might not be perfect. It definitely isn’t working.

Update after some experimentation:
With the help of Cameron Hurd, I tried the following code:

add_action('woocommerce_new_order', 'custom_process_order', 10, 1);

function custom_process_order($order_id) {
    $order = new WC_Order( $order_id );
    $items = $order->get_items();
    foreach ($items as $item) {
        if ($item->get_id() === 10766) {
            $order->remove_item( $item->get_id() );
        }
    }

    $order->save_items();

    return $order_id;
}

This seemed promising, but pressing the checkout button will submit an empty order while also throwing an empty WooCommerce error message leaving the user on the checkout page.

After this I had 2 ideas:
1.) Changing remove_item to wc_delete_order_item. I really don’t know the difference and changing it didn’t seem to make a difference either.
2.) Changing the hook so it happens after the order is in the back end. I tried changing it from woocommerce_new_order to woocommerce_thankyou. This however broke the thank you page in addition to doing nothing to the order.

This is what I’m sitting with now:

add_action('woocommerce_checkout_create_order', 'custom_process_order', 10, 1);

function custom_process_order($order_id) {
    $order = new WC_Order( $order_id );
    $items = $order->get_items();
    foreach ($items as $item) {
        $current_item_id = $item->get_id();
        if ( $current_item_id === 10766) {
            $order->remove_item($current_item_id);
        }
    }

    $order->save_items();

    return $order_id;
}

Still looking for a working answer.

Answer

You could use the woocommerce_checkout_order_processed action hook, where you then specify the product id.

So you get:

function custom_process_order( $order_id ) {
    if( ! $order_id ) return;

    // get order object
    $order = new WC_Order( $order_id );
    
    // get order items = each product in the order
    $items = $order->get_items();

    foreach ( $items as $item ) {
        $product = wc_get_product( $item['product_id'] );
        
        if ( $product->get_id() == 10766 ) {
            $order->remove_item( $item->get_id() );
        }
    }
    
    // Calculate
    $order->calculate_totals();
    
    // Save
    $order->save();
}
add_action( 'woocommerce_checkout_order_processed', 'custom_process_order', 10, 1 );