So I wanted to do it in Portal, and I did, so Put this into your Config
bind "r" "ent_remove_all prop_portal; play weapons\portalgun\portal_close2.wav;
You can change the Closing sound as well if youd like
I dont know if it will work if you type it in console, I forgot the console command to bind it so youll have to add it to your config, Other wise ENJOY 

