You need Brouzouf now?
You need experience now?
You need to know why I asked this question again?
All that can be answered with one thing.
http://gamebanana.com/maps/159542
"Place the .bsp file into your common/eye/EYE/Maps folder." - directly from the download page, written by UKRed.
All those other methods require some special weapons and actual skill, but who needs that when you can just borderline cheat and use this map!

• Go to the main menu
  
• Launch Temple HQ
  
• Hit ~
  
• Type "changelevel cm_farm_alpha_23" and hit enter. No "quotation marks"
  
• Enjoy

Sermon is your guy if you want to hang out with friends while grinding and actually put in some effort for Brouzouf and levels!
Its a map where you can summon waves of monsters at your own pace, giving you tons upon tons of Brouzouf and XP.
You can also pick ~4 songs before each round and get research spawns at the same time. And if the last wave wasn't enough Brouzouf for you, you can hack the Infernal ATM to acquire some more.
Waves will usually be the normal monsters, but will sometimes randomly change to feds, culter, jians, or looters. But it doesn't matter! Just more Brouzouf.
A server should be up as of writing this, so go ahead and play on it if you don't like cc_farm_alpha23 or don't like the cold and unforgiving loneliness.
Personally, I suggest buying turrets before playing on here. Once on, fill your inventory with as many turrets as possible, then place them in front of the staircase to the spawn. Activate the wave and stand anywhere you want! Spray your minigun while knowing that there's no way the enemies can possible bum-rush you and destroy you. You can also psi-clone if you want.
Downloads and versions if you want to host it for yourself or do it solo: https://steamproxy.com/app/91700/discussions/0/620700960551872902/

Credits:
https://steamproxy.com/id/kon_air for making Sermon.
Not much else that wasn't already addressed. Maybe /cyg/ for giving this game a boost in popularity.