You can add the line activating debug mode to your userstartup.cheat if you have one.
The hack you're talking about was probably
See Them 2. Be careful if you already have a userstartup.cheat as this mod overwrites it. Make sure you make a backup of your userstartup.cheat first so you can restore any other commands you had in there yourself. Or just edit it yourself, as I said above.