How to edit cart timeout/expiry

I want the cart to empty itself after x minutes so as to avoid hoarding.

I changed session expiration in /woocommerce/classes/class-wc-session-handler.php from 48 hours to 20 seconds for testing, but it doesn’t seem to work.

Also, how do I get “WC Debug” under Tools?

https://www.ads-software.com/plugins/woocommerce/