change products per page on specific pages woocommerce

Hello!

I have found the bellow two codes but i cant get them to work...
I want to change the number of displayed products in specifically 5 product categories (change the number from 12 to 30)
Only on those 5 though and not in any other!

add_filter( 'option_generate_woocommerce_settings', 'tu_custom_wc_columns' );
function tu_custom_wc_columns( $options ) {
    if ( ! is_product_category( 'audio' ) ) {
        $options['columns'] = 2;
    }

    return $options;
}

From Tom (past thread)

/**
 * Change number of products that are displayed per page (shop page)
 */
add_filter( 'loop_shop_per_page', 'new_loop_shop_per_page', 20 );

function new_loop_shop_per_page( $products ) {
  // Return the number of products you wanna show per page.
  $products = 100;
  return $products;
}

From wordpress.stack-exchange

I made those 2 like this

add_filter( 'option_generate_woocommerce_settings', 'tu_custom_wc_columns' );
function tu_custom_wc_columns( $products ) {
    if ( ! is_product_category( 'νοσοκομειακα-κρεβατια' ) ) {
        $products = 30;
    }

    return $products;
}

And i did some other combinations with no luck... This one breaks the styling, and the other one i tried changed it globally to 30 and not just to the one i tested it...

Do you have any insights on this?
Thank you for your time!