/**
 * Prohibit a specific product to specific states
 */
function custom_add_validation_rules_products() {

	if ( ! isset( WC()->cart ) ) {
		return;
	}

	$shipping_country    = WC()->customer->get_shipping_country();
	$shipping_state      = WC()->customer->get_shipping_state();
	$cart_contents       = WC()->cart->cart_contents;
	$cart_product_ids    = wp_list_pluck( $cart_contents, 'product_id' );
	$prohibited_products = array( 188, 189 ); // Add prohibited product IDs here
	$prohibited_states   = array( 'HI', 'AK' ); // Add prohibited states here

	// Invalidate when trying to ship a specific products to prohibited states
	if ( 'US' == $shipping_country && in_array( $shipping_state, $prohibited_states ) && array_intersect( $prohibited_products, $cart_product_ids ) ) {
		wc_add_notice( __( 'There are some products in your cart that cannot be shipped to your location.' ), 'error' );
	}

}
add_action( 'woocommerce_checkout_process', 'custom_add_validation_rules_products' );