I made a Vigilante Char before the ID Repninja... Spent around 20 hours shooting NPCs to get myself Hostile to all unlawful factions (And still couldn't get the clean result I wanted). Now I see if there was such a command back then, I could do it in 20 mins! (Although the Vigilante ID is repninja now, right?)
And maybe, make the effect of this command permanent (Just like FR5s) so it won't be abused for getting Guard Rep. So, if you type /hostile zoners, you'll stay hostile with them on that char... Much like Self-FR5ing.